Posts Tagged ‘Audio Forensic Expert’

Cloud Storage for Evidence Sharing

Tuesday, March 13th, 2012

Cloud-Storage-1024x768 Cloud Storage for Evidence SharingAbout a week ago I was called by Wired Magazine and interviewed about cloud storage for evidence sharing. My first thought was that cloud storage is a great technological advance and is very convenient for the courts, police and lawyers who all need copies of audio and video forensic evidence.  Then I thought about the chain of custody problem.

I have found that courts and litigators still take audio and video evidence lightly depending on who is presenting the evidence. When authenticated by a forensic expert, audio and video evidence can be a very important tool in the court room.

I have experienced incredible turn around decisions when video evidence is shown in court to a jury.  Video is like bringing the scene of the crime into the court room.  Of course this works for both defense and prosecution in criminal cases as well as civil cases.

It is a hassle for some courts and police departments to authenticate audio and video forensic evidence as well as to maintain a chain of custody.  There is one big problem with cloud storage and audio and video evidence: maintaining a chain of custody of any evidence uploaded and downloaded to and from any type of cloud storage.

On the other hand, I can see benefits to having the evidence available 24|7 for all persons involved in the litigation. A formal procedure will have to be established in order to make cloud sharing of audio and video evidence available.

For example, if the prosecution and defense were each issued a user name and password, the cloud storage service could monitor access as well as maintain the integrity of the original audio or video evidence.  This would be fairly simple since most audio and video evidence is in digital form.

It all boils down to both sides agreeing on the identity of the original.  If the original is not disputed and can be shared and tracked in a cloud storage environment, then cloud sharing of audio and video evidence can work.  Once a dispute arises then the cloud storage environment will face forensic investigation to determine proper chain of custody.




photo credit: Dropbox via photopin (license)

What is an Audio Video Expert Witness?

Friday, February 17th, 2012

audio-video-forensic-expert-1024x680 What is an Audio Video Expert Witness?Because there is more audio video evidence being presented in the court system today than ever before, there is a need for professionals to specialize in audio video forensics.  A professional who has been practicing audio and video engineering for ten or more years has the experience and expertise to understand the technical aspects of any audio and video recordings.  I have been a practicing audio engineer since 1978 and video engineer since high school video class which began in 1975.  Back in those days everything that was recorded was analog.  Even video was recorded on reel to reel spools of metal particle nylon video recording tape.

A person is not considered an expert witness because of technical experience alone. An audio video expert witness must have litigation experience.  I began my litigation experience in 1973 working as a probation officer for the 52-2 district court in Troy Michigan.  I minored in criminal justice while attending the University of Detroit.  The legal system always intrigued me.

While employed as an audio engineer at Ambience Recordings which used to be located in Farmington Hills, Michigan, I was working with a client–the FBI–on a criminal case in Detroit. They needed background noise removed from a confidential informant wired recording so the court could hear the conversation as it was recorded. The device that was used to make the recording was a miniature reel to reel recorder with 3” tape hubs.  The informant wore the microphone near his mouth and the recorder was hidden on his body.

I played the recordings from the Nagra reel to reel recorder into our studio’s mixing board.  I then patched in an external equalizer and reduced the background noise by lowering the frequency in the spectrum where noise was and raising the frequency where the voices were.  Once I had the external equipment calibrated, I transferred that recording to another Skully reel to reel recorder and made a restored master.

This activity is technical experience.  Young people who approach me about becoming a forensic expert always want to know what it takes to be an expert witness.  I tell them technical and litigation experience. The easy part is the technical training; the harder part is the litigation experience.

I was quickly becoming a real audio forensic expert. There was not much in the way of video evidence in litigation. However, my first video forensic case came in the form of a hidden camera video recording an employee stealing from the employer.   That is when I had the pleasure of meeting Steve Cain.  I went to Williams Bay Wisconsin and spent a week with Mr. Cain while he examined the video recording.  He was retained by the defendant and I was retained by the plaintiff.

I realized that week that I knew more about video than I gave myself credit for.  After all I had video production in high school and then in college.  This experience with Mr. Cain made me realize that a video forensic expert was responsible for authenticating video evidence, restoring poor quality video footage, looking for anomalies or edits in the recording and using external electronic devices as tools for the forensic examination process.

Back then, everything was non-computer.  Since then, I have had continuing education with the American College of Forensic Examiners International and I have become a registered investigator.  I have also taken CCTV, digital video certification and other expert witness training which is also a very important characteristic for expert witnesses. Technology changes and the expert witness must keep up with the current trends and new technology of all aspects of audio and video in order to maintain their expert status.

Soon after those early forensic experiences I was actively referred by other experts in the industry including Steve Cain because of my expertise and qualifications.

I became quite experienced testifying and when I took the stand and said what needed to be said about an audio or video recording, I was considered confident. I have been successful for almost 28 years now.

When you are looking for an audio video forensic expert, remember that having an expert who has testified as an audio expert as well as video expert will add credibility to your case and help the court as well as all parties in the litigation better understand the evidence and how it pertains to the facts as they actually occurred.

Audio Evidence

Tuesday, November 30th, 2010

5230479916_345e8050b3_o-1024x682 Audio EvidenceAudio evidence as well as video evidence is any recording that has been admitted and accepted into a litigation and is an account of events as they occurred.

Audio evidence includes confidential informant recordings, recordings of confession by officials, telephone intercept or wiretap, voice mail and 911 calls. The goal of the forensic expert is to process the recordings for forensic enhancement and or forensic authentication and analysis.

One step in the forensic authentication process of video recordings is to be sure a chain of custody has been established. Also, is the recording used as evidence an original or a copy? The audio portion of a video recording is also examined forensically when performing forensic video authentication.

This was important back when analogue recordings were primarily used as evidence.  This is because the audio portion of a video recording holds many clues for the forensic examiner. It is especially important today with digital recordings being the primary format for audio evidence.  Once the digital recording has been burned to a CD, it is no longer considered an original. Especially if anybody objects to its authenticity. It is considered a digital duplicate as long as all parties in the litigation agree to its contents and what it pro-ports to show. It is much more appropriate to use the original recording because it can be forensically authenticated when it is in its original environment.

There is no reason that an original digital audio recording cannot be preserved in the equipment that created it.

Digital audio recordings take up very little space and can easily remain stored on the equipment that created it. It is NOT okay to erase or delete the original so the recording equipment has more storage space. In the case of a digital pocket recorder deleting content to make room may be a logical thought process until somebody objects to its authenticity.

In some cases, a deleted audio recording could be considered spoliation of evidence if a forensic expert can not effectively authenticate the audio evidence. A CD copy is technically not an original because once the audio recording is removed from its native environment.  Often times, this alteration can go undetected even by an experience audio forensic expert. This is why preserving the original file of the audio evidence is extremely important.

Whether you are law enforcement presenting a confidential informant or confession audio recording, a private individual presenting a voice mail or concealed audio recording, always preserve the original recording so there is no doubt of the authenticity and integrity of the audio evidence.  Consult an experienced audio forensic expert to assist you in authenticating the audio evidence for a fair and accurate representation of the facts as they occurred in their original environment.

photo credit: Mixer board via photopin (license)

Video Forensic Expert Edward J Primeau Curriculum Vitae


sidebar map
sidebar video
forensic associations