Primeau Forensics Blog

The Importance of Establishing a Chain of Custody for Audio/Video Evidence

chain of custodyEstablishing a chain of custody is the first step in any audio or video forensic investigation. This includes audio/video forensic enhancement, audio/video authentication and voice identification. Where did the evidence come from? Who created the recording that is being entered into evidence?

A chain of custody is the documentation of who did what to evidence and when was it done. A chain of custody includes people, dates, places, activity and the recording of that information to establish the chain of custody. What has been done since the evidence was created? The chain of custody refers to both digital and analogue audio or video evidence.

The chain of custody for a piece of evidence is important to the legal community because it adds credibility to the audio/video evidence. However, it is common for law enforcement and others in the legal community to often overlook establishing a chain for audio/video evidence. It’s not because of neglect but more often due to lack of training or understanding the importance of the process.

Unfortunately, audio/video recordings are sometimes entered into evidence without documenting the evidence recovery process. When this is the case, if both parties agree that the evidence is acceptable, and tamper free, the audio/video recording is established as the ‘original’ and the chain of custody begins there.

An audio/video chain of custody begins with the evidence recovery process. This is the process of forensically removing the original audio/video recording from the recorder that created it. Based on our experience at Primeau Forensics, once both parties in a criminal or civil litigation agree on an original, they request each side’s forensic expert to establish a protocol for recovering the audio/video evidence. This protocol is written step by step instructions created by one of the experts, then negotiated and or modified and revised until the protocol is established.

Over the last 32 years practicing as lead expert at Primeau Forensics, Ed Primeau has worked with evidence recordings from client lawyers who received recordings from the police. Whenever evidence is not retrieved personally, the police reports, depositions, and other court documents that accompany the evidence must be carefully read to understand how it was acquired. This paper trail must establish a timeline; a chronological listing that accounts for the recovery, custody, transfer and storage of the evidence because the lack of an established chain of custody can easily overturn a conviction on appeal.

Ronald Johnson and Laquan McDonald – WGN9 Chicago Interview

There are two Chicago Police Department shooting videos that have been in the news lately, Laquan McDonald and Ronald Johnson.

On November 24, 2015, police video that captured the shooting of Laquan McDonald in Chicago, Illinois was released to the public, almost 13 months after the incident took place. There has been a public outcry regarding not only the death of McDonald, but also the videos themselves.

Ronald Johnson was shot and killed by police officers in October of 2014 while fleeing into a Chicago public park. It is debated whether Johnson was armed or not. Over a year later, video footage was finally released after months of Johnson’s family pushing for the footage to be made public.

In an interview this morning on WGN Chicago, our lead audio video forensic expert Ed Primeau explained the importance of video in both cases. He also discusses the low quality of video that has been presented to the public, as well as the role of a video forensic expert.

22: Audio Enhancement – Equalization

EqualizerEqualizers can be one of the most important tools to any audio engineer, and especially an Audio Forensic Expert. There are many different types of equalizers with different capabilities, but the core functions are always the same. Equalizers allow the user to increase or decrease the level of different frequency ranges or ‘frequency bands.’ Each frequency band is typically marked by its center frequency, while the width of the band will vary between different equalizers. Some equalizers even allow the frequency band and the width to be adjusted.

Having these controls at your disposal when performing an audio enhancement is crucial. Noise and other extraneous frequency content is usually the biggest issue with audio recordings. Equalizers and filters offer the ability to remove narrow ranges of frequencies so that these noises can, for the most part, be removed from the recording while leaving other frequencies untouched.

When using an equalizer, it’s important to be careful boosting and cutting different ranges. Sometimes removing a certain noise may sound helpful at first, but there could also be a lot of important voice content in the same range. Making the proper adjustments with an equalizer requires both experience with the equipment, critical listening skills, and a lot of trial and error. The more time you spend working with audio and equalizers, the more familiar you will become with different frequency ranges and how to best go about improving the quality of different recordings.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the use of equalizers in forensic audio enhancements.

21: Audio Enhancement – Compression

As an Audio Forensic Expert, knowing what tools are available to me and how they work is extremely important. While compressors are often thought of as tools for music production, they serve many functions in the Audio Forensic world. Like with most audio signal processors, it takes training and experience to operate compressors properly and effectively when enhancing audio.

When an audio enhancement is required, the recorded signal is often very low, or the desired source is unbalanced, with other signals in the recording. Compressors can increase the gain of a recording while also balancing the levels of the sound sources. While different compressors will vary, most have the same basic controls. These include the threshold, attack, release, ratio and makeup gain.

It is easy to focus on raising the level of the desired signal with a compressor and produce a loud, but unintelligible work product. Sometimes a smaller amount of compression may have a more positive effect on the audio. An experienced Audio Forensic Expert will know how to effectively clarify the recording based on his or her knowledge of audio and signal processing.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the use of compressors in forensic audio enhancements.

20: Body-worn Cameras with Sgt. Bill Tilson

police body camerasSgt. Bill Tilson is a police officer with the Coeur d’Alene Police Department in Coeur d’Alene, Idaho. He has been working in the department since September 2002 and began working with body-worn cameras in 2012 when the department began issuing them to officers. He received a Bachelors degree in Criminal Justice and Corrections from Lewis-Clark State College and an Associates degree in Criminal Justice and Law Enforcement Administration from the College of Southern Idaho.

Sgt. Tilson has seen first hand the benefits of body-worn cameras in law enforcement and has been a major part of their integration into the Coeur d’Alene Police Department. He has also dealt with many of the struggles that police departments are facing with the large amount of video that is being captured by these body cameras.

Now listen in with Ed Primeau and Sgt. Bill Tilson as they discuss the benefits of body-worn cameras, the issues with storing the video, chain of custody procedures, and Federal standards for maintaining the video evidence.

photo credit: USCP4.NSM.Rally.USCG.WDC.19apr08 via photopin (license)

19: Audio Enhancement – Noise Reduction

noise reductionMost recordings that I come across as an Audio Forensic Expert are made in poor condition and their biggest problem is an abundance of noise. Though there are many ways to reduce the noise floor in a recording, there is no guaranteed method. The noise floor can be defined as a sum of all of the unwanted signals in a sound source. This will include any background noise in an environment such as cars driving by, televisions or radios, or even other people besides the desired person speaking.

When reducing the noise is the best option, there are two common ways to do so in most audio editing software: noise reduction processing and filtering or equalization. Both processes have benefits and side effects when used to remove noise from a recording.

The most important thing to remember when removing noise from a recording is that the goal is to enhance or clarify the desired signal. Every audio recording is different, and as an Audio Forensic Expert it is my job to analyze and process each recording as needed. It takes training and experience to recognize what a recording needs in order to enhance or clarify it effectively.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the use of noise reduction in forensic audio enhancements.

photo credit: Neve Compressors via photopin (license)

The Importance of Forensic Transcription

transcriptOver the last 31 years as Audio/Video Forensic Experts, Primeau Forensics has developed a tool to help litigators better hear and comprehend poor quality audio recordings that are to be used in court. We are very good at audio enhancement and helping our clients know the best method of audio playback in the courtroom so everyone can hear the audio recording being played during the litigation. In hard to hear situations, a forensic transcript, signed by an audio forensic expert can be invaluable.

A forensic transcript usually begins with forensic audio enhancement which is the process of using various software programs and expert filtering to remove the unwanted sounds and increase the volume and intelligibility of the wanted sounds which are usually conversations. Background noise includes noisy furnaces, air conditioners, buzzes and hums, traffic and wind. Once the recording has been enhanced, the forensic expert uses a combination of studio grade speakers, computer speakers, headphones and ear buds to comprehend and transcribe the conversation.

A forensic transcript is a signed and declared ‘under the pains and penalties of perjury’ document of a conversation that occurred in a hard to hear recording. Even after a digital recording has been processed for audio forensic enhancement, it may be difficult to hear the entire conversation. A forensic transcript is prepared by an audio forensic expert using critical listening skills, the same expertise used for voice identification and speaker recognition. Then when the enhanced digital audio recording is played in court, the written transcript can be followed during the playback of the enhanced audio recording so everyone in can understand what is being said.

The forensic transcript can also be notarized which in a sense certifies it as ‘true and accurate beyond a reasonable degree of scientific certainty’. Each forensic transcript assignment we complete at Primeau Forensics is quoted based on the amount of audio enhancement that is required for the audio recording restoration and time it will take to listen and document the words spoken in the recorded conversation.

Forensic transcription is not limited to audio recordings. Primeau Forensics has transcribed video recordings as well. We load the video recording into our forensic computer and remove the audio track. Once the audio has been enhanced, we post the clean restored audio back onto the video. Now we have a video enhancement to help with the litigation. In some cases, we have also added the words from the forensic transcript onto the screen to read as the video is playing. One such time we used this technology was when we restored and transcribed the Air Force One audio recordings the day John F Kennedy (JFK) was assassinated. See sample of this technology below:

Air Force One Recordings from John F Kennedy (JFK) Assassination on Vimeo

18: Creating Video Work Product as an Audio Video Forensic Expert

video work productVideo work product is a way to document forensic investigations, like evidence recovery, for reference at a later date. Processes and procedures are documented using a video camera by a forensic expert during a forensic investigation for future use. I have referred back to my video work product many times during the course of a case when I have questions later in the evolution of the case. There are a few different digital video recording platforms that I use when creating ‘video work product’. Each one of these types of systems serves a certain purpose in assisting with a forensic investigation as well as the investigative process.

I personally use the VIEVU LE2 and LE3 body worn cameras. My main use for this body camera in my investigations is recording my forensic process in the field. This includes retrieving evidence from different systems so I can review the video later and include in my report to support the authenticity of my work product and any evidence used in the case.

Another type of digital video camera that I use to produce video recordings is a HDSLR photography camera. In some investigations, a single video recorded perspective may not be sufficient to display the forensic process or document the events. Having another high quality camera with flexibility of perspectives and interchangeable lenses can capture aspects of my investigation that body worn cameras cannot.

Video evidence produced by CCTV systems can help solve crime, as well as reproduce accidents and disasters as they occurred for play back in many different settings. A significant use a video forensic expert has when recording video from a CCTV system is to create an exemplar. This recording is used as a comparison file to the original evidence to help determine the authenticity of the original evidence.

It is a best practice of ours at Primeau Forensics to video record many forensic investigations like the exemplar creation process and evidence recovery so if anyone has any questions during the life of the case, this video work product can be referenced.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses creating Video Work Product for Forensic Investigations.

17: How to Make Digital Audio Evidence

digital audio evidenceAudio evidence can often be one of the most important pieces of evidence for a case, so it should always be given a great deal of attention. I’m going to cover some tips on how to create the best audio recording possible, whether it’s a police interview, a concealed recording or anything in between.

One of the most common ways people create digital audio evidence is by using digital audio recorders. Law enforcement will often use them for interrogations and confessions, and sometimes even out in the field as a backup for their dash cam or body cam audio. People outside of law enforcement use them for creating audio evidence as well.

Tips on Creating Digital Audio Recordings

  1. Choose settings on the digital recorder that optimize the quality of the audio and optimize the amount of space on the recorder.
  2. Listen and note any extraneous noise present in the area before making the recording. If at all possible, remove this sound or find a way to work around it.
  3. Get as close to the desired sound source as possible when creating the audio recording. The closer the microphone is to the sound source, the better the level of the desired signal will be.
  4. Make sure the digital audio recorder is in an optimal location. Make sure that the microphone is facing the subject and that the recorder is relatively stable to avoid extra noise. If possible, use an external microphone to get better quality audio.
  5. Always create a test recording before the actual recording. Listen back carefully and adjust the settings of the recording and the location of the recorder to make sure it is capturing the highest possible level in the best quality.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the best practices for creating digital audio evidence.

photo credit: Ready to record! via photopin (license)

16: VIEVU Body Cameras with Steve Ward

Steve Ward is the CEO and founder of VIEVU.  He worked as a police officer in Seattle for 13 years, including 6 years on the SWAT team. Afterwards, Mr. Ward became the Vice President of Marketing and International Sales for Taser International. He has an MBA from the Edinburgh Business School, a Certificate from the University of Chicago’s Graduate School of Business and a Bachelor’s degree from the University of Oregon.  Steve Ward founded VIEVU in 2007, which manufactures high definition, wearable video cameras for law enforcement and private professionals.  These camera systems have become necessary when considering the liability present in law enforcement, and also provide strong evidence for use in court.

Steve Ward is dedicated to making VIEVU cameras the most optimal body cameras for police officers and continues to provide the most updated and cutting edge hardware and software with his cameras.  VIEVU currently provides body cameras to 16 different countries and is one of the leading companies providing body worn cameras in the United States.

Now listen in as Ed Primeau and Steve Ward discuss VIEVU and the growing need for body camera video in law enforcement.

15: A Step-by-Step Approach to Forensic Audio Enhancement

audio enhancementOne of the most common jobs for an Audio Forensic Expert is enhancing a digital audio recording for intelligibility and clarification.  Audio evidence is often recorded in less than optimal situations with poor quality equipment. This evidence can be vital to a case and when the content of the recording cannot be heard, the evidence can become useless.  This is why the audio enhancement process is one of the most important jobs as an Audio Forensic Expert.

There is no one way to enhance an audio recording because every recording is different and will have its own issues that make the enhancement process necessary. At the same time, it is important for the Forensic Expert to be aware of the processes available so they are prepared to handle any enhancement case that comes their way.

Critical Listening

To begin the enhancement process, the Forensic Expert should use critical listening.  Before adding any processing to the audio, they should listen through the recording multiple times and make notes on the issues they hear with the recording.  Noting different sections of the audio and marking these points can be extremely helpful when fixing different problems in the recording.

Diagnostic Tools

Some audio software includes processors that help fix clipping or clicking issues in the recording.  Using this process first will help clean up the audio as much as possible before delving into more advanced techniques.  Noise reduction is also a very helpful process for removing any background noise such that is consistent throughout the recording.

Dynamics Processing

Many recordings I receive have an overall low level to begin with and simply need an increase in gain. Compressors as well as gain plugins can help raise the overall level of the recording. Compression will also help balance all of the signals in the recording.

Equalization

Equalization is another extremely helpful tool for audio enhancement.  This will allow the Forensic Expert to remove unwanted frequencies and frequency ranges by varying amounts, as well as boost desired frequencies. When using an equalizer, the Forensic Expert should experiment using their knowledge of frequencies and what they see in the recording.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the structured approach to forensic audio enhancements.

 

14: Video Surveillance with David Spreadborough

CCTVDavid Spreadborough is a CCTV investigator and a police officer for the Cheshire Police Department in Cheshire, England.  He has been a part of the police force for 23 years and began his video forensic career in 2003.  David is a member of the Law Enforcement & Emergency Services Video Association International (LEVA), the National Policing Improvement Agency (NPIA), the CCTV National Standards Forum and he sat on the Association of Chief Police Officers (ACPO) Working Group for CCTV.  David has taken multiple training courses covering Forensic Video Analysis, CCTV installation and retrieval and Multimedia Evidence Processing. He focuses on CCTV video evidence and has spent the last few years working with CCTV manufacturers to improve the quality of systems as well as the installation and accessibility for law enforcement.

Up until November of 2014, David was the Senior Officer within the Visual Forensic Unit in the Cheshire Police Department and oversaw all major crime video investigations in the department.  It was then decided that Police Officers could no longer hold Forensic positions within the department.  David is currently looking forward to finding new ways to use his expertise as a Forensic Video Investigator and welcomes anyone who is interested in learning more about the field to contact him.

David is dedicated to the development of Forensic Video Analysis and working with new technology to improve the field.  If you would like to contact David, you can find him on linkedin.

Now listen in as Audio and Video Forensic Expert Ed Primeau and Officer David Spreadborough discuss the importance of CCTV systems for law enforcement, the advancements made in video surveillance over the last decade and the challenges being faced by Video Forensic Experts today.

13: Voice Identification with Maria do Carmo Gargaglione

Screen Shot 2015-05-28 at 4.09.10 PMMaria do Carmo Gargaglione is the Director of the Division of Digital and Technological Forensic Evidence at the Public Ministry of Rio De Janeiro.  She has been a speech-language pathologist for over thirty years.  She is an expert in voice identification, facial identification and handwriting analysis.  She began working in forensics in 2000 and began working for the Public Ministry in 2005. Since then, she has continued her education in the field of digital media forensics at any given opportunity, including the courses at the National Center for Media Forensics at the University of Colorado.  She was the first in Brazil to begin a division of digital media evidence with voice identification.

If you would like to contact Maria do Carmo, she can be reached by email at maglione@globo.com.

Now listen in as Maria do Carmo and Ed Primeau discuss different techniques used for voice identification, the importance of digital forensic work in Brazil, and advice for people interested in starting a career as an Audio Forensic Expert.

For more on Voice Identification, check out Ed Primeau’s latest book, “That’s Not My Voice!” available on Amazon.

12: Video Forensics with Dorothy Stout

dorothy stoutDorothy Stout is a Video Forensic Expert and owner of Resolution Video Inc.  She has been analyzing video since 1998 and has testified in all levels of courts in the United States.  Dorothy received her Bachelor degree in Psychology and her Masters in Forensic Science and began her career at the US Postal Inspection Service.  She has also performed Video Analysis for the US Department of Defense Computer Forensic Laboratory and has worked with the International Association of Chiefs of Police and the Security Industry Association.  Resolution Video Inc. was founded in 2004 and has continued to provide audio and video enhancement, analysis, authentication and training services for law enforcement agencies.  Dorothy is currently an adjunct professor at George Washington University, the University of Indianapolis, and the British Columbia Institute of Technology. She also teaches training workshops around the country on both Audio and Video Forensic work.

Dorothy Stout makes sure her company demonstrates integrity, impartiality, diligence and professionalism in their work, which has made her one of the leading Video Forensic Experts in the country. If you would like to contact Dorothy or Resolution Video, they can be reached online at resvid.com or by phone at 703-759-7803.

Now listen in as Dorothy Stout and Ed Primeau discuss the effect video evidence has had on law enforcement, the challenges and limitations faced by Video Forensic Experts and the importance of connecting with other experts when beginning your career as a Forensic Expert.

 

11: Talking Forensics with Audio & Video Forensic Expert Allen Combs

allenAllen Combs is an Audio and Video Forensic Expert with over ten years of experience in multimedia work.  He began working as an audio engineer in recording studios and continued working in music production until making the transition into digital media forensics.  When he began his forensic work, Allen was trained by Thomas Owen and in 2010 started his own company, Combs Forensic Services.  Since then, he has worked for numerous clients, including both law enforcement and private citizens, and has gained experience testifying in many of his cases.  Allen is an active member of the American College of Forensic Examiners, the American Board of Recorded Evidence and the Audio Engineering Society.  In addition to these organizations, he is also putting together an audio forensic training course with Dorothy Stout, owner of Resolution Video.

Allen Combs bases his company on integrity, professional expertise and dedication to their clientele.  If you would like to contact Allen or Combs Forensic Services, they can be reached through combsforensics.com or allen@combsforensics.com.

Now listen in as Ed Primeau and Allen Combs discuss the drastically changing market of Audio Engineering, the importance of continuing education in the digital media forensic field, and the challenges that individuals must face when taking on a career as a forensic expert.

10: How to Authenticate Digital Audio Evidence

digital audio evidenceAuthenticating digital audio evidence and the importance of the authentication process for use in court. The chain of custody is the first step in the authentication process but does not in and of itself authenticate a piece of evidence. I have seen audio evidence that was not authentic and was stored in the original digital audio recorder that supposedly recorded it.

So why is audio authentication so important? 

The authentication process determines whether or not the audio recording in question has been tampered with.  In this age of digital audio, edits can be made and covered up very easily. There are free versions of audio editing software available on line that can make edits that alter the events or conversation that originally occurred in digital audio recordings. Most of the time, if an audio recording is edited after downloading to a computer and before authoring a CD, the editing can be detected by analyzing the audio file.

What is the process of authenticating digital audio evidence?

There are five steps that one must complete to properly authenticate digital audio evidence.

1. Establish a chain of custody. If the expert is able to retrieve the evidence from the original source, in most cases that will automatically create and establish a chain of custody. If it’s not possible for the forensic expert to retrieve the recording, then the forensic expert must carefully go through all of the documents and reports that arrived with the evidence. When the chain of custody cannot be established, the forensic examiner must rely on other techniques as well as their own expertise to determine the authenticity of the evidence.

2. Critically listen to the audio recording. During this process the expert should note unusual sounding sections in the recording, referred to as anomalies. They should place markers near any anomalies they hear for later reference when compiling a forensic report. Inconsistencies in sound quality, noise floor, and level of the recording are all important to pay attention to.  The forensic expert should use both studio monitors and headphones with flat frequency responses to best hear everything that is going on in the recording.

3. Electronically measure aspects of the recording. The forensic expert should use the audio forensic software they have to note the frequency ranges, levels and other aspects of the recording. Marking what frequency ranges voices or other sounds are in compared to the noise floor can also help the expert better detect sudden changes and other anomalies in the recording that may indicate tampering.

4. Visually inspect the audio recording. This step will go hand in hand with electronic measurement. The forensic expert should analyze the waveform characteristics and look for any anomalies present. The expert can also use spectrum analysis and spectrograms to better see the behavior of the frequencies and detect breaks or changes in the signal or noise floor.

5. Analyze the metadataThe forensic expert will also need to inspect digital information of the recording such as the hex information, sampling rate, bit depth and file format. This will need to be compared with an exemplar recording so that anomalies can be properly detected. Digital footprints are almost always left on recordings when they are created and when they are edited using other software.

For a forensic examiner to authenticate a piece of audio evidence, the examiner must prove beyond any doubt that the recording is in its original form and has not undergone any tampering.  If a piece of evidence is not authentic, it should not be used in court because it may be incomplete or altered to purport events that did not occur.

9: How to Recover Digital Media Evidence

evidence retrieval I’d like to discuss evidence recovery, specifically digital media evidence recovery.  Having a forensic expert retrieve the evidence maintains the quality of the evidence and can help ensure that the original evidence stays intact on the original system so it can later be retrieved by other parties.  This is why it is extremely important that only a trained expert retrieve the evidence.  In this episode, I will cover proper procedures for evidence retrieval, proper handling of the evidence and what precautions one should take when retrieving digital media evidence from a recording system.

Steps for Proper Evidence Retrieval

1. Research before retrieving the evidence.  The forensic expert should learn everything they can about the recording system beforehand.  Connecting with the manufacturer, reading the manual and researching further online all benefit the expert.  This will make analyzing and operating the system onsite easier for the expert and optimize the retrieval process.

2. Obtain any necessary software, proprietary player or codec. If the system records proprietary or encoded files, the expert should obtain the player or codec beforehand.  If that is not possible, the expert should be prepared to install the necessary player or codec onsite from either the recording system or client.  More often than not, modern digital surveillance systems require a special codec or proprietary player and without this installed, the forensic expert will not be able to access the digital media evidence.

3. Record the evidence retrieval process. The forensic expert should record both audio and video of the evidence retrieval to include in the chain of custody and forensic report.  When I am recovering evidence from a digital recording system, I always have a VIEVU body camera on my person, as well as a digital audio recorder in my pocket.  Along with authenticating the evidence, this can serve as the expert’s notes later on in the investigation in case they need to refer to something that was discussed during the evidence retrieval.

4. Photograph and inspect the digital recording system. The forensic expert should include photographs of the unit in their report and take careful notes on anything they notice about the unit.  This could include damage, tampering or any other abnormalities they notice on the recorder.  Along with the video recording, it is usually beneficial for the expert to photograph anything they note during the process.

5. Follow the manual for the highest quality retrieval. The expert should have the manual with them when retrieving the evidence to make sure that any copy or export is in the highest quality format and does not affect the original recorded file.
photo credit: iLike iRiver via photopin (license)

8: How to Give an Expert Deposition

depositionDepositions are one of the most important activities performed by forensic experts, second only to the final testimony.  A deposition is the process where the opposing lawyers question the forensic expert, under oath, about what they are going to testify during trial.  These questions are designed for the opposing lawyer to gain information about the investigation that the forensic expert performed, to learn what the expert would testify about in court.

Just like testifying in court, it is very important for the forensic expert to prepare beforehand for the deposition.  Carefully sifting through his or her investigation with a fine tooth comb, and reviewing all investigative notes can make a large difference on their success when being deposed.  The forensic expert should also work with their client lawyer directly to learn what information the opposing lawyer will be most interested in and how to properly express their answers.

Ten Tips for Giving a Good Deposition

  1. The forensic expert should dress professionally.  I always wear a suit and tie when being deposed.
  2. The expert should only answer the questions that are asked.  They should avoid elaborating too much on their answers in order to avoid giving away too much information.
  3. The forensic expert should always prepare with their client lawyer.  The lawyer will always know more about the case and what information should be shared.
  4. The expert should be aware of anyone attending the deposition remotely and make sure to make eye contact with him or her through the camera being used in the system.
  5. The forensic expert should speak clearly so the court reporter can accurately type everything they say during the deposition.  Sitting close to the court reporter if possible can greatly help.
  6. The expert should always obtain a copy of the transcript to make sure all of the information is accurate.
  7. The expert should arrive early to the deposition.  They may not know the location well and allowing extra time can save the expert from being late.
  8. The expert should bring a current copy of their curriculum vitae to make sure that it is presented as part of the deposition.
  9. The expert should have all of their notes ready in front of them as well as their forensic report.  Any evidence that needs to be presented should be ready as well.  If evidence needs to be presented from a computer, the expert should make sure that it is working properly beforehand.
  10. Finally, the forensic expert should practice their deposition.  Even beyond rehearsing with their client lawyer, the expert should go through all of their notes and reports prior to being deposed.  They should spend time the night before double-checking all of their information to ensure they are ready for the deposition.  More often than not, this can make a difference in the deposition.

Listen in with Audio and Video Forensic Expert Ed Primeau as he discusses how to properly prepare for and give a good deposition.

7: Importance of the Chain of Custody for Digital Media Evidence

chain of custodyEstablishing chain of custody when authenticating digital media evidence for use in the courtroom is extremely important. The chain of custody must account for the seizure, storage, transfer and condition of the evidence.  The chain of custody is absolutely necessary for admissible evidence in court.

Importance to the expert

My forensic software allows me to look at the metadata or digital information of an audio or video recording, but does not always allow me to understand how a recording was created.  Just because the information is missing from the metadata does not mean that a recording has been compromised.  This is why the chain of custody information is important to a forensic examiner. It helps show where the file came from, who created it, and the type of equipment that was used.  That way, if I want to create an exemplar, I can get that equipment, create the exemplar and compare it to the evidence to confirm the file properties.

Importance to the court

When I testify in court with a piece of evidence, I am always prepared with the chain of custody.  As I mentioned earlier, without a complete chain of custody, it can become very easy for the opposing attorney or prosecutor to challenge or dismiss the evidence presented.  Having a complete chain of custody form, as well as any other accompanying forms and including any visual proof of retrieval, such as pictures or video, greatly helps prove the authenticity and admissibility of the evidence in the courtroom.

Recently, new ways of establishing a chain of custody have come about and are slowly becoming accepted in the legal community.  Online services are now available for digital evidence that record the chain of custody and who has received the evidence.  The evidence is stored in cloud space and eliminates the need for repeated transference of physical copies.  It maintains standardized security procedures and is also useful as a backup storage space for surveillance cameras.

Chain of custody is important to the court because if I find something wrong with the evidence during the authentication process, it allows me to go back and determine who was responsible for the evidence up until that point. 

Importance to the investigation

The chain of custody is important to the investigation process because it is the first step when authenticating digital audio and video evidence.  Identifying this chain of custody provides information about whether or not this evidence has been copied or cloned.  As technology advances and becomes more accessible, digital media evidence has become easier to edit, modify and alter.  The Scientific Working Group on Digital Evidence (SWGDE & IOCE) defines Original Digital Evidence as, “Physical items and the data objects associated with such items at the time of acquisition or seizure.”  It is not always possible to receive the evidence from its original source at the time of acquisition or seizure.  Very often, I receive digital media evidence from a client who may have received it from the police or another source.  When this occurs, I have to pay careful attention to the reports, depositions and other legal documents that accompany the evidence.  This paper trail must be part of an unbroken timeline that shows exactly where the evidence has been between its creation and my examination of it.  When I encounter any gaps in this timeline that can raise questions to the authenticity of the evidence, further investigation becomes necessary.

There are occasions when I am asked by the client to physically retrieve the evidence directly from the recorder that created it.  This process creates the chain of custody for my investigation.  When an expert creates the chain of custody, it removes all doubt as to the authenticity of the evidence.   This process has become more common throughout my investigations when the original evidence is available for my retrieval.  To further authenticate this process, I create audio and video recordings of the retrieval process, which becomes part of the chain of custody. In addition, when I am at the site and I retrieve the digital evidence, I have access to the administrator information about that evidence, such as an administrative log, date and file info, and who accessed the files.  The more information an expert can retrieve strengthens the authentic chain of custody that is created.

Primeau Forensics’ chain of custody process

  • Save original package materials
  • Take photos of physical evidence
  • Take screenshots of digital evidence content
  • Document date, time and any other information of receipt
  • Ingest a bit for bit clone of digital evidence content into our forensic computers
  • Perform a hash test analysis to further authenticate working clone

All of the above information outlined in our forensic procedure for creating a chain of custody is important and necessary to include when creating a forensic report.

When examining digital media evidence, especially digital audio and video recordings, you should never examine the original file.  Always make sure that when you process a piece of evidence, you work on the copy of that file so that the original remains untouched at all times.  That way, if you have to go back to compare your work product to the original, you’ll have that original file preserved.

It doesn’t matter what forensic science you are an expert in.  The chain of custody is always important.  Maintaining that chain of custody is crucial for the credibility of your work product and eventual testimony.

6: Continuing Education as a Forensic Expert

continuing educationAs a forensic expert, continuing your education in your field of expertise is extremely important in remaining a credible forensic expert.  I practice audio and video forensic work and at the rate that technology is evolving, it’s important for me to stay up to date on all of the latest advancements in the field. This is not exclusive to digital media forensics.  New developments are made in all areas of expertise.  Being an expert witness requires you to have current and accurate knowledge in your field of expertise.

When an expert witness is first called to the stand in a courtroom, their client lawyer will begin with the direct examination.  During this, the lawyer will ask questions that establish the expert witness’s qualifications and credentials.  After the direct examination, the opposing prosecutor or attorney will question the witness and challenge them as an expert witness.  The more experience and credentials you have in your field, the harder it becomes for the opposing attorney to disqualify you as an expert witness. Certifications and diplomas are documented proof of your relevance and credibility as an expert in your field.

Get involved in organizations related to your field.

I am a member of the American College of Forensic Examiners Institute and am on the advisory board of Recorded Evidence.  We help determine the qualifications for Audio Forensic Experts and are currently updating the test to become certified.  It is extremely important be forward thinking when managing your career as a forensic expert.  Its not enough to be status quo when you are a forensic expert. You have to have the most accurate and up to date knowledge and be able to apply that knowledge to remain a credible forensic expert.

Now listen in with Audio and Video Forensic Expert Ed Primeau as he discusses the importance of continuing your education in your field as a forensic expert.

Video Forensic Expert – The Importance of Continuing Education

continuing educationI have been practicing as a video forensic expert for 30 years. I have experienced and observed hundreds of hours, if not days, of security video. I have performed video forensic testing on analogue and digital security systems. I have even forensically examined cell and smart phone video, tablet video and VHS, Hi8 and 8mm, digital 8mm, digital and analogue beta and even ¾” video (which by the way plays from right to left unlike any other analogue video format). I write this introduction not to impress you, but rather express to you that I have been around the block a few times.

However, this week I experienced something new. I took a continuing education class in ‘Digital Video Processing Techniques’ taught by Dorothy Stout of Resolution Video Inc.

On the first day, we were asked to introduce ourselves and say what we expected to learn from the class. When it was my turn, I introduced myself and said ‘I don’t know what I don’t know. That is why I am here, to learn what I don’t know.’

Any forensic expert who thinks they know everything about their expertise is arrogant, especially in video forensics where technology is constantly changing. Dorothy took our class through three days of very interesting lectures about digital video processing techniques, software training and actual security video hands on assignments. Her demeanor and teaching style in the front of the class made these three days very invigorating. Learning was fun and easy thanks to Dorothy’s experience. She is sought out by government agencies, law enforcement and private practice video forensic experts like myself all over the country for video forensic training.

I learned about software programs, work flow, case management and most importantly, had my confidence boosted because I had already known quite a bit about the various video forensic processes that we covered and practiced.

Anyone with a passion for video forensics should consider taking one of Dorothy’s video forensic classes. I learned a lot and enjoyed the experience.

5: How to Perform a Voice Identification

voice identification Voice Identification (also known as Speaker Recognition) plays a very important part in the forensic world.  I practice voice identification regularly as an Audio Forensic Expert and I believe it is a viable and often crucial science when working on a forensic assignment.  I chose this topic for this podcast because I just released my new book “That’s Not My Voice!: A Practical Understanding of the Art and Science of Modern Voice Identification.”  In my book, I cover the basics of human hearing and my approach to voice identification.

How do you perform a voice identification?

The process of voice identification is done through multiple steps.  The first step is critical listening.  When you first receive a recording from a client, its important to listen through the recording in its entirety and take detailed notes on what you hear.  In order to continue with the voice identification process, an exemplar is needed as a comparison to the recording in question.  Exemplars are supervised recordings of predetermined spoken word samples strictly made for voice identification comparison.  Electronic measurement has become possible with audio software that include spectrum graphs.  This allows you gather notes on specific information on the frequency ranges of the two recordings.  Visual inspection of the waveform should be done next.  During this step, you will analyze and compare the waveform of each recording.  Words will have different lengths and varying levels for different syllables in the words.

Emergency Voice Identifications are cases where creating an exemplar of the voice in question is not an option.  This is typically when a threat has been called in to a company and they believe they know who called in the threat.  In these cases, I must use any possible recording of the accused person such as a recorded voice mail or outgoing voice message.  These are difficult cases but it is very important that the company stay in control of the situation before approaching the suspected person.

Now listen in with Ed Primeau as he discusses the Voice Identification and the steps that must be taken to accurately and effectively perform the process.

For more on Voice Identification, check out Ed Primeau’s latest book, “That’s Not My Voice!” available on Amazon.

4: Forensic Science – How to Prepare to be an Expert Witness

expert witnessBecoming an expert witness is a challenging step for a forensic expert. In an earlier post we talked about putting together your CV and its importance in building your credibility as a forensic expert. Now, we will go over the how to prepare yourself and your team for trial and what to expect when testifying in the courtroom.  Not all forensic experts decide to become expert witnesses and appear in court.  There are many qualified experts who choose to avoid the stress of testifying and focus on the outside forensic work that they specialize in.  Testifying in court is challenging and requires a lot of preparation to withstand the pressure of the courtroom.

Personally, I have found that there are two aspects to my career as a forensic expert.  The first is my forensic talent, which I make sure to continuously improve by furthering my education in the field every year.  The second is testifying.  This skill almost outweighs an expert’s laboratory experience.  This requires you to not only know your field of expertise but also know how to act in the courtroom.  I have worked on and testified in dozens of forensic assignments and court cases, which has helped build my reputation and credibility as an expert witness.

In this episode, we’ll go over the importance of completing forensic assignments and testifying, the courtroom experience, what it means to be under oath, preparation for the trial, how to dress and act when testifying, how to best answer questions while on the stand, the direct examination and the cross examination.

Now, listen in with Audio and Video Forensic Expert Ed Primeau as he discusses what to expect when becoming an expert witness and testifying in court.

3: Forensic Science – Writing Your Forensic Report

writing your forensic reportThe forensic report is a forensic experts full report of their work on a case for court.  It includes everything the forensic expert did while examining the evidence along with their findings throughout the investigation.  In this post, we will briefly talk with Chicago trial attorney Shawn Warner about the importance of the forensic report and what makes a great forensic report. The examples I will use today are about combining forensic sciences and forensic clues to help develop and process a case for trial.

Analyzing all information and determining what process to use are typical for most forensic investigations.  Building the forensic report is key in preparing for trial.  The forensic report contains all of the work that was put into your investigation and covers all of the facts for the case.  This ensures that nothing is left out of an expert witness’s deposition or testimony.

I use audio and video forensics in combination quite often. The publicized shooting of a firefighter on his wedding night by an off duty Kansas City Police Officer is an example where I combined forensic sciences in order to bring out the facts of the shooting. I was given a cell phone video recorded by a witness.  The video included much of the confrontation but not the entire confrontation.  I could hear the dialogue between the two men in the cell phone audio. One of the first things I did after I loaded this cell phone video into Adobe Premiere Pro CS 6 was develop and process the audio portion of the video to better hear the words spoken. Next I loaded a second video I was given which was from a nearby CCTV camera across the street in a parking garage.  Then I synced the two videos together so the viewer could see and hear all the events as they occurred in both recordings.

In this weeks podcast, listen in with Audio & Video Forensic Expert Ed Primeau as he talks about the importance of a forensic report and its importance in a case.

2: Forensic Science – How Attorneys Select Forensic Experts

forensic expertShawn Warner is a 25 year veteran Chicago trial lawyer. In this post, we are going to discuss the role of the forensic expert. Why hire a forensic expert? What do lawyers look for when hiring a forensic expert?

Shawn Warner is licensed in Illinois but also works on cases across the United States.  He has worked on many medical malpractice cases, personal injury cases and business litigation.  He frequently employs expert witnesses to testify in court.  Shawn has gathered knowledge on what qualifies an expert witness to testify in court, what juries expect and accept in expert witnesses, and helpful tips on how expert witnesses should approach their testimony in court.  Many of his previous cases have proved how invaluable a forensic expert can be when helping the jury understand and reach a verdict on the case. Forensic experts help explain complicated issues brought into the court room so that the jury can understand the case and reach a decision.  They must have real world experience as well as a strong education to prove that they are an expert in their field.

In this weeks podcast, listen in with Audio & Video Forensic Expert Ed Primeau and Chicago Trial Lawyer Shawn Warner as they discuss the qualifications and importance of Forensic Expert Witnesses in court.

1: Forensic Science – How to Build Your Expert Witness Curriculum Vitae (C/V)

Curriculum VitaeMy name is Ed Primeau and I am an audio video forensic expert. I develop or process audio and video evidence to better hear and see the events as they occurred in the audio or video recording. I also authenticate audio and video evidence to learn if the evidence presented is real and can be used in court. I also conduct modern voice identification.

In this first episode of ‘Blindspot’, I want to cover an overview of the qualifications of a forensic expert. If you are thinking of a career as a forensic expert, you better begin with a solid foundation in your area of expertise. This is on the job experience, activity both behind a desk and in the field. Your forensic career will grow as your work experience grows. To document this experience, as forensic experts we create what is referred to as a curriculum vitae which is a Latin word meaning ‘the course of life’ in other words, things that have happened in your life. A C/V is a document that lists your education, work experience, articles published and reviewed by your peers as well as continuing education and associates you belong to. Eventually your C/V will also list the legal cases you have word on and successfully completed.

So where do you begin with creating your C/V?

As a forensic expert, your C/V is the most important and most used document you will ever have as a forensic expert. This is the document that will allow everyone who reads it an understanding of your education and experience as well as life accomplishments as a forensic expert. The reader will know your experience and how it relates to the work you are doing or have already completed. Your C/V is also very important when qualifying you testify in court. Your C/V is also an integrity foundation. Forensic experts must have integrity.

In this weeks podcast, listen in with Audio & Video Forensic Expert Ed Primeau as he talks about the importance of a C/V and it’s role in your professional career as a forensic expert.

How to Hire a Lawyer

hiring a lawyerAfter 30 years as an audio and video forensic expert, I know about the good and the not-so-good lawyers. It seems to me, based on firsthand experience, that there are more ‘not-so-good’ lawyers. This inspired me to compose a blog post on how to hire a lawyer. 

The first point I want to make is that if you have a lawyer that you feel is not doing the best job for you in your case, fire them and get a better lawyer. You may even be entitled to a partial refund of the retainer you paid them when they took your case. For questions on this, consult your state licensing board’s grievance commission. Here is a link for cases in Michigan http://www.agcmi.com/

A good lawyer knows how to balance their time. They avoid taking calls when they are with clients, providing them with their undivided attention. The not-so-good lawyers answer their phone during client meetings. This brings up another problem, lawyers that do not have assistants. Every good lawyer has somebody to answer their phone and help with coordination of details in your legal matter.

A good lawyer will be firm with you when you run on with crazy ideas that seem to tell them how to do their job. A not-so-good lawyer may yell at you or avoid you all together. Remember, many lawyers take cases based on flat fees. In this situation, don’t abuse the lawyer’s time. Good lawyers will tell you their trial strategy days before your court room appearance. Not-so-good lawyers tell you their trial strategy the morning of your court date.

Good lawyers plan, not-so-good lawyers wing it. I have worked with lawyers who juggle multiple cases in the same courthouse simultaneously. How can a lawyer be a good lawyer when they are multitasking?

This may be OK for parking tickets and other related minor driving offences, but when you have a criminal case that could land you in jail, this is unacceptable.

Good lawyers dress well and are respected by those in the courts where they practice. Not-so-good lawyers show up in court with wrinkled shirts that don’t fit so well or with their hair messed up. Appearance is extremely important in court for not only yourself, but also your lawyer.

So how do you hire a good lawyer in the first place? By asking a lot of questions before you sign the check. Ask for references and call those references. Go to their office instead of meeting them over coffee at Tim Horton’s. A lawyer’s office speaks volumes about their practice. If you cannot afford a good lawyer, the court will appoint you one. In this case you don’t have much choice. You have to take what you can get. However, in some cases you can tell the court why you would like a new lawyer assigned to you. Keep a list of dates and details before you file that complaint.

When meeting with a lawyer for the first time, bring a list of questions and write down their answers. Beware of lawyers who take big cases for small flat fees. Chances are they don’t have the ability to handle your case and will more than likely let you down. Good trial lawyers are worth their weight in gold.

There are different levels of lawyers who specialize in different aspects of law practice. There are general practice lawyers who handle drunk driving, domestic disputes, traffic tickets and divorce. There are other lawyers that handle IRS disputes or those that are experts at child custody. Some lawyers handle criminal law. These lawyers are very experienced and usually charge a higher rate than the previous lawyers mentioned.

Once you have interviewed at least three lawyers that you are considering, review the facts before you make your decision. Which lawyer impressed you the most? Which lawyer did you best connect with? Which lawyer almost blew you off?

Lastly, do not let the pending litigation distract your decision making skills. Do not be blindsided into picking a lawyer because you are in a hurry. Make your decision based on fact as well as gut feeling.

photo credit: Historic 9th District Court of Appeals via photopin (license)

Expert Witness Preparation

expert witness preparation As an audio and video forensic expert, I often have to give depositions and also testify. A few years ago my courtroom activity was minimal. Today, it seems like more and more cases are going to trial. Prosecutor pleas are not being accepted and civil litigators are too far apart for settlement.

When the time comes for me to testify, I always carve out time to prepare on my own as well as with the client attorney. I begin by reviewing the evidence, audio or video. Then I read all communication between myself and the client. Lastly, I read my reports. When I meet with the attorney, I begin by asking them to discuss their top concerns about the case and my deposition.

One very valuable lesson I have learned is to rehearse every aspect of the testimony with the client lawyer. This includes my Voir Dire. According to Forensic magazine, ‘The voir dire examination is typically based upon perfunctory questioning about institutional affiliation and publications. The expert witness performs two primary functions: 1) the scientific function — collecting, testing, and evaluating evidence and forming an opinion as to that evidence; and 2) the forensic function — communicating that opinion and its basis to the judge and jury. A general rule of evidence is that witnesses may only testify to what they have personally observed or encountered through their five senses.

I take the time to prepare a list of questions for the client lawyer to ask me when testifying that helps them understand my credentials. When we meet to discuss my testimony prior to testifying, we add to that list based on the lawyers concerns and experience with the case.

Audio and video forensics can be technical by nature and every once in awhile I am faced with opposing counsel that has really done their homework. One particular case happened recently where opposing counsel asked me a series of questions that were misleading in order to trip me up during a deposition. I knew the answers but was distracted by their condescending line of questioning. It caught me off guard and later I realized that I should have rehearsed this potentially harmful line of questioning.

I was asked about the science of my investigation. I had already answered by observation and experience. When the opposing counsel kept asking I thought he was digging deeper to learn the mechanics of the equipment that I had not yet investigated. In hindsight, I should have repeated my answer instead of trying to figure out the operational science on the spot. I knew the answer but was cornered because he was extremely prepared to find a weak spot in my testimony.

I have had cases where client lawyers tell me that we do not have to prepare. I push hard and offer options for our pre trial rehearsal. I have learned to ask, ‘Would you like to meet the night before or the morning of the trial?’

One last point is to always anticipate the cross examination questions and prepare your answers well in advance. That way, when you are under oath, your testimony will be smooth and nearly complete during direct examination.

Spend as much time preparing for your testimony as necessary. Since your client depends on your preparation and experience, you owe it to them to do your absolute best. Since your reputation depends on your testimony, do not feel that you must be compensated for every minute of your preparation. In fact, it’s always a good idea to give more than you have been compensated for. I like to refer to that as going the extra mile. As an audio forensic expert , video forensic expert, or any other expert witness, it’s mandatory to be prepared for testimony. Do not be distracted by the monetary aspect of your business when it comes to preparation.

The Forensic Expert Witness: 3 Tips For Preparing to Testify

Proficiency in their field is certainly a prerequisite for all who testify in court as an expert witness. But now, with the benefit of 25 years experience, I believe that a good expert witness must also qualify as an expert in communicating clearly and persuasively on the witness stand. In short, expertise in testifying is just as important as expertise in a particular field of knowledge. Here, then, are 4 tips for expert witnesses and the attorneys they work with.

 

Tip #1

Make sure that the judge and jury are fully convinced that you are, without any doubt, a true expert in your field. Proving your status as a recognized, fully qualified expert is the foundation upon which all your testimony rests. The more impressive your credentials, the greater the weight given to your testimony. For that reason, I always have several copies of my CV available for review by opposing counsel, judge, and jurors, as well as a copy that is entered into evidence.Always supply the attorneys on your side with a clear outline of facts designed to help establish your credibility as an expert witness. You can even provide them with a list of suggested questions that will help substantiate your qualifications in a succinct, logical manner. It has been my experience that if I do not earn the respect and trust of the jury before presenting the facts, then my testimony will fall on deaf ears. Similarly, make a list or an outline of the order and substance of the points you plan to make, and provide it to the attorneys who have engaged you as an expert witness. There is no one more qualified than you to suggest a line of questioning to follow during your direct examination. You have a broad overview of the beginning, middle, and end of your investigation, the story of what you found and how you found it. By their very nature, people are constantly attempting to make sense of their experience. Psychologists have found that one of the ways they do this is by creating narratives, forging links between the facts of their experience and creating causal chains. If the story you present is a good one, if it is clear and compelling, then the jury will remember it and give it the credence it deserves. Especially in cases where there are many facts to bring out, a detailed outline serves as a road map for the attorney to follow. Under the pressure of appearing in court, it is surprisingly easy to overlook important facts that must be highlighted during your testimony.

Tip #2

Sitting alone, I always rehearse aloud what I want to say when I testify. This helps me remember the order in which I want to present my findings. More importantly, it allows me to practice explaining, in simple language, the results of my investigation. My goal is to present, explain, and illustrate my findings so that the average 12-year old can understand me. Juries are easily bored by technical jargon and obscure scientific concepts. I strive to be clear and concise, and to allow the natural enthusiasm I have for my area of expertise to show through. People love to learn about new things(though this flame is often extinguished by the time they graduate from high school).One of my favorite film directors, Stanley Kubrick, once said, “To be boring is the worst sin of all.” Our world is alive with facts and ideas, emotions and events. Life is inherently interesting. Appearing as an expert witness should not give someone license to put the jury to sleep.

Tip #3

Extremely valuable is conducting a mock trial. I recently testified as a video forensics expert in one of the most complex cases of my career. We spent two days on a mock trial, with one lawyer doing direct and another cross. Over time, I was able to answer every question clearly and without hesitation, even those questions that challenged my findings and expertise. By the second day, we had arrived at a list of all the questions the prosecutor would be most likely to ask during cross-examination. At trial, the prosecution had only two questions for me, because we had already answered most of his questions on direct examination. Anticipating and pre-empting questions from the opposition is a highly effective legal strategy. Because it was complete and candid, my testimony was largely immune to challenge from the prosecution. A trial consists of many large and small battles, which determine the outcome of the war, the verdict. In that sense, my testimony was an overwhelming victory for our side.

Establishing a Chain of Custody for Audio and Video Evidence

chain of custodyAs a Registered Investigator and Certified Forensic Consultant in audio and video analysis, I am often called upon to testify as an expert witness for either the prosecution or the defense. My job is to offer an authoritative analysis of electronic evidence, introduced in the form of audio or video recordings. The content of my testimony is twofold, interpretation and authentication. I interpret and clarify the recordings, and I authenticate the identity of those individuals seen and heard. But I must also authenticate the evidence as evidence. Has this recording been tampered with? Is the recording I examined the original or a copy? Through whose hands has this recording passed before and after it reached me? Where and how has it been stored?

The answers to these questions may determine the admissibility of the electronic evidence, and ultimately, whether a defendant is found guilty or innocent. Establishing and maintaining an unbroken chain of custody is vital. Without it, the evidence and my testimony, no matter its probative value, may be successfully challenged and ruled inadmissible. According to the online IT Law Wikia, chain of custody is defined as “a process that tracks the movement of evidence through its collection, safeguarding, and analysis lifecycle by documenting each person who handled the evidence, the date/time it was collected or transferred, and the purpose for the transfer.”

I always make a video recording of my process/investigation when I retrieve evidence. For example, if the video evidence is on a digital video recorder, I travel to the DVR and personally retrieve the evidence myself. The video I record of my retrieval process effectively establishes a chain of custody. Of course, I follow the same procedure when I personally retrieve an audio recording.

However, there are many instances where I obtain evidence from lawyers who, in turn, receive recordings from the police. Whenever I do not retrieve the evidence personally, I must carefully read the reports, depositions, and related documents that accompany the evidence I receive. This paper trail must support the construction of a timeline, an unbroken, chronological listing that accounts for the seizure, custody, transfer, storage, and condition of the evidence. The timeline must be free of any gaps, periods of time during which the exact custody and location of the evidence cannot be accounted for. A weak link in the chain of custody can easily overturn a conviction on appeal, so I am always prepared for chain of custody questions when I testify.

A typical chain of custody form includes blank text fields that allow for the entry of the following: Case Name and Number, Type of Evidence, Evidence Initially Procured (Where, By Whom, Date & Time), Manufacturer and Serial Number of Media Device and/or Media, and a table listing Evidence Inventoried By (Name, Date, Time, ID), Evidence Released By (Name, Date, Time), and Evidence Received By (Name, Date, Time).

As I mentioned earlier, there are actually two chains of custody when considering electronic evidence: the physical recording itself and the data it holds. With the proliferation of home computers capable of desktop audio and video editing, there has been an increasing incidence of tampering with recordings before they are collected as evidence. I can usually spot recordings that have been altered very quickly, once I begin my electronic analysis.

Slowly gaining acceptance with law enforcement, security companies, and the legal community are online services that maintain and track the chain of custody of electronic evidence, which is stored in the cloud. Particularly useful for the archiving and storage of video from body cams, vehicle cameras, and surveillance cameras, these services hope to modernize the handling of electronic evidence by eliminating the repeated transference of physical evidence, maintaining standardized security procedures, and providing easy access to the content of electronic recordings.

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