Posts Tagged ‘original evidence’

Original Digital Media Evidence is Mandatory

Saturday, February 5th, 2011

original digital mediaDigital audio is recorded and stored in electronic equipment. If the audio is needed in court, the original device that created the recording must be identified and kept in a chain of custody. The only exception is when both parties involved in the litigation agree that a copy is sufficient. If there is doubt in the authenticity, the audio expert must refer to the original to support the authentication of the audio evidence.

The reason is that the audio copy has been removed from its original environment and is vulnerable to alteration. In addition, if a computer created the original recording, additional information can be examined by the audio expert such as file creation, last accessed and other computer forensic information that can support the audio evidence authenticity.

If the original audio recording was created in a digital pocket recorder (which many law enforcement officials use) then that original pocket recorder must maintain a chain of custody and become the original evidence. Any external copy created by a number of methods and played outside of the digital pocket recorder is a copy. Unless an audio expert can authenticate the copy (which can be done once the original has been examined) it cannot be used in a court proceeding. If the audio copy has been authenticated by an expert, than it will be easier to play and amplify in the court for a judge and jury.

I have testified in criminal cases for the defense when the client swore under oath that the audio recording had been altered and did not represent the facts as they occurred. Now it’s their word against the other side and when the court has to decide, the prosecution most always, will prevail.

If you have had an experience with audio evidence and would like to share your story, please comment on this post and your story will be heard.

Audio Evidence

Tuesday, November 30th, 2010

chain of custodyAudio evidence can include but is not limited to confidential informant recordings, confession recordings, telephone intercept, voice mail and 911 calls. The goal of the forensic examiner is to be sure a chain of custody has been maintained like any other evidence and that the original recording is used as evidence and not a copy.

This was important back when analogue audio recordings were primarily used as evidence.  It is especially important today with digital audio being the primary format for audio evidence.  Once the digital audio file has been burned to a CD, it is no longer considered an original because it has been removed from its native environment (computer or pocket digital recorder). Furthermore, the audio file can be authenticated when it is in its original environment.

There is no reason that an original digital audio recording cannot be preserved when a legal proceeding is expected or may occur.  The rationale that it is ok to erase or delete the original so the recording equipment, in the case of a digital pocket recorder, could be reused is not a logical thought process. In many cases, this could be considered as spoliation of evidence.  A CD copy is not original because once the audio recording is removed from its native environment; the audio evidence is vulnerable to alteration and editing.  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 recorded 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.

sidebar map
sidebar video
forensic associations aes member