Posts Tagged ‘Forensic Investigation’

Audio Forensic Expert Report Writing

Monday, May 6th, 2013

forensic report writingAll forensic experts write reports. Some reports are better than others. What goes into a ‘better than other’ forensic report? Depending on the forensic investigation, opening the forensic report with the credibility building language is an important starting point. Here is a sample of how I open my audio forensic reports:

I am an audio forensic expert and have been practicing for 29+ years. I have testified in several courts throughout the United States and worked on various international cases. My forensic practices include audio authentication, restoration and voice identification.

The next step in the forensic report is to include the evidence you were provided by your client to forensically examine, as well as what you were asked to do. This paragraph must be documented and described in detail. Here is a sample of how I draft this section:

On or about March, 25, 2011 I received a CD from your office that contains a 911 call recording. You asked that I investigate the recording to determine if it contains one or two voices at the scene of the crime.

I listened to the CD and heard the initial voice that spoke and the second questionable voice in the background, noting that it sounded different from the first voice. I suggested making arrangements to create an exact exemplar of the suspect for comparison purposes in this forensic investigation.

On Tuesday, April 23, you and I arranged to create an exemplar of the suspect’s voice to comparewith the initial 911 call first voice. The exemplar was created using as much of the same electronics as possible that were used in the original 911 call recording. Also featured in the exemplar were the exact cell phone and the same person that placed the original 911 call.

In addition, we also recorded exemplars of other persons who could have made this 911 call for comparisonpurposes in a voice identification line up.


This above outline is an example. Much of the language might not make sense but the text still exemplifies the message I am communicating about audio forensic reports.

The next part includes your investigation; what you did as an audio forensic expert and the opinions you arrived at. This investigative process must list all activity, testing and the software programs, hardware and other tools, scientifically describing in detail all tests so that another forensic expert with similar qualifications can recreate your testing and arrive at conclusions.

In a case where the opposite side in the litigation has retained a forensic expert, that forensic expert will want to review your investigation and findings to determine how to strategize the court proceeding based on this information as well as your opinion. I have worked on cases where the forensics experts were disagreeing with each other before the trial, and others where forensic experts were disqualified before trial. This is why forensic report writing is crucial and one of the most critical parts of any forensic investigation.

The fourth component in the forensic report is the expert’s conclusions; often times this conclusion is ‘based on a reasonable degree of scientific certainty’. The audio forensic expert reports the truth about the evidence in question or another characteristic in question about the audio evidence. The conclusion is a statement of scientific fact and opinions expressed about the conclusion of scientific fact must be presented in simple English for all triers of fact and other expert witnesses to easily understand.

When the forensic report is submitted, it should also include any work product, sub files and the most recent CV (curriculum Vita). If the case is older, chances are the expert has updated their CV since beginning the forensic investigation.

If you have an audio forensic concern and would like more information about the investigating process with regard to report writing, call or write for a pro bono consultation.

Release or Destroy Audio Evidence After Litigation

Wednesday, January 16th, 2013

audio evidenceAn audio forensic expert listens to audio recordings of litigation points during a forensic investigation. Oftentimes, these audio recordings are very sensitive in nature. They are crucial to the litigation and must be destroyed or returned to their provider once the litigation is complete. Generally, in civil litigations, settlements are reached based on a series of conditions. One of those conditions is often that all of the evidence be destroyed that was used to process that litigation. It is very important that the audio forensic expert stay in good communication with their lawyer contact to make sure that they clearly understand what to do with the audio evidence once the litigation is complete.

If that audio evidence were to become available to the wrong people after the litigation settlement it could violate and have other ramifications to the terms and conditions of the settlement. That’s why it is very important for the forensic examiner to know what is expected of them from the attorney and other litigators regarding that forensic evidence.

In the past I’ve received letters from attorneys asking me to dispose of the audio evidence I used to investigate their case. In my professional opinion, there are only two options for an audio forensic expert for dealing with the evidence they examined upon reaching a settlement in the litigation.

One, return the evidence back to the attorney or your contact person in the case. Signature required, delivery confirmation is essential so that the forensic expert has proof that it was returned to the appropriate party. Second, destroying the evidence by physically breaking or destroying the playing surface on a compact disc, which is the most common media for delivering the audio recordings to be examined by the forensic expert. Or delete files stored in computer hard drives or other external storage devices, such as a thumb drive.

So, we either return the evidence to the contact person, signature required so that we have confirmation and proof of delivery; or we dispose of the evidence by destroying the compact disc or delete from external storage device. It is best, if possible, to get their instructions in writing (particularly if the instructions are to destroy the evidence), just to protect yourself and make sure all your bases are covered.

I recently had a case that settled and I was contacted by someone who identified himself as a friend of one of the litigators, and claimed to have permission to listen to part of the audio recording that I investigated for this litigation. I denied the (alleged) friend access to the recording and contacted the party who retained me for the investigation and let them know I was being contacted. The huge problem here is that, had I given the audio evidence to the person that contacted me not only could I have jeopardized my reputation in the forensic community if this person had released that evidence, it would also have had a huge ramification on the settlement for my client because, that audio evidence being compromised, would also violate the conditions of his litigation settlement (not to mention opening myself up to a possible lawsuit for releasing the audio evidence to an unauthorized party).

Bottom line, when the forensic expert completes a forensic examination, it is the forensic examiner’s responsibility to determine what to do with the evidence that they have investigated so that it does not fall into the wrong hands and violate the terms of the litigation settlement.

photo credit: Salat via photopin (license)

Forensic Investigation: Court Recorded Digital Audio Files

Friday, March 2nd, 2012

court recordingsWhen I am asked to investigate alterations of court recordings, I almost always travel to the courthouse to examine the court’s computer recording system. It is not often that I examine audio files recorded in court from a remote location. This is a serious allegation and requires careful scientific investigation and proof if the accuser is to prevail in court.

For example, I had a client request that I examine court recorded digital audio files they believed were altered. Portions were alleged to have been deleted. These court recordings were created with a software program “For The Record.”

FTR has propitiatory CODEC (a form of audio encryption) wrapped around .WAV digital audio files. One day’s worth of court proceedings will yield a lot of digital audio files.

I began this remote forensic investigation by downloading the FTR player after registering as a user on their website

These digital audio files are automatically created based on the length of the recording and number of microphones active during the recording.  My client believed portions of the court testimony as it pertained to her case were missing from the audio file folder that is burned to her CD.

When a serious accusation arises against a court of law, as a forensic expert, I have to make certain I have scientific evidence of alteration, missing files or tampering before I can report to my client confirmation on the alleged alteration.

After conducting forensic testing on the “For The Record Player” I have confirmed that deleting .WAV audio files from the record folder will cause the recording to adjust playback.  In other words, portions of the recording would be missing if I delete any of the .WAV files from the folder my client sent me.

Did the court delete the file or were they accidentally left off the CD my client gave me?

I cannot determine from a CD if any files were deleted. I can determine however that deleting files from that record folder will cause portions of the recording to “not be an accurate representation of the facts as they occurred.” The only way to be certain the court deleted or accidentally did not transfer all the files from that trial onto the CD is to examine the original files on the computer that created the files at the courthouse.

No matter who is involved in the case, every  allegation of deleting evidence nust be handled with the same scientific procedures.

photo credit: Dan Moody’s Courtroom – ! via photopin (license)

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