Three methods to preserve media for evidentiary value

People say that the law is slow and rigid to accept evolving technology. But recorded audio and video as well has been admissible to many years. So how do you avoid issues with evidence and improve it’s quality?

Has the recording been altered?
With analogue audio recordings it was easier to validate an altered recording than with digital. But don’t worry is is still possible for an audio expert to tell if the recording was edited or if something may have been omitted. The same holds true for video if you need to verify if the recording was or was not altered.

Was it enhanced?
Most courts will accept enhance media as long as you also submit the original un-enhanced version as well. If the media was enhanced it may be very important to have the technician describe the process of enhancement.

Today almost all recorded media is digital. Unlike analogue recordings that degrade in quality, each copy that is made a digital recording can maintain quality over many generations of copies.

What can cause digital copies to degrade in quality?


  • Changing the media format
  • Compression losses – un-compressing the recording and re-compressing in a new format
  • A bad copy
bad video

Bad video resulting from compression and copy errors


Know this, every time a compressed video is copied into a new format the quality is degraded, and today most video recordings are compressed to save space on digital recording storage. So I recommend you get the original recording or an exact digital copy of it of the media file. If the original recording was on a memory card for a body camera, for example, and you receive a DVD for a DVD player, it will have been decompressed and then compressed again so therefore  degraded. So acquire an exact digital copy of the recorded file and get a written description of the original format of the recording and details of the process of how the copy was made.

The challenge is preserving the images and captured audio for evidentiary value. We have become a surveillance society and as technology advances for police departments and the general public, certain evidentiary concerns need to be considered.