Thursday, July 02, 2009

CCTV Evidence Challenges

While CCTV videos can be key pieces of evidence, a number of challenges in obtaining and using CCTV footage is common. This post examines some of the most common problems in using CCTV video:

  • Retrieving Video: There are hundreds of different manufacturers of CCTV systems and very few work the same way. If you need to retrieve video, you have to find someone who knows how to use that particular system.
  • Playing Back Video: Many CCTV systems use their own proprietary video compression. This can cause problems in trying to play back the video. Finding the codec for that system's compression can be difficult. It's best to always ask for video to be shared in AVI format (that can be played back on any media player). Even better is to get the video packaged in a self-enclosed player. Many PCs (especially in law enforcement) have restrictions on applications installed. Putting the video in a self-enclosed player means that you can click the video file and run it without installing anything.
  • Verifying Video Authenticity: Again, CCTV systems vary in how they verify the authenticity of video, proving that the video has not been tampered. Some video systems have no way to do this. Others apply a simply overlay on the video. The most secure calculate a digital key when creating the video (though this is rare). There's no common technique for CCTV video verification. If this is important to a case you are working on, you will need to check the specifics of the system where the video was recorded.
  • Video No Longer Available: Very frequently, video clips will not be available after a short period of time. This varies by the user but some only keep video for 7 days and most do not keep video longer than 30 days. If you really need the evidence, push to get it right away before the video is overwritten.

If you have other questions or issues on CCTV evidence, leave a comment and I will be happy to provide more recommendations, My site, IP Video Market Info, is the world's leading resource on CCTV/video surveillance. For those who need in-depth information on surveillance cameras, video analytics, monitoring and more, the site may be able to help.

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