Two days ago I was asked to speak on the subject of forensic audio and video to about forty attorneys at the office of the San Diego Public Defender. Thirty attorneys attended in person and the other ten were watching live streaming from their branch offices.
I believe all lawyers present learned a great deal about security camera surveillance video evidence; a good sign they were engaged is that they asked great questions.
One interesting question from a lawyer in the audience can be summarized as: “Today, with even smartphones recording video at HD, with amazing resolution and detail, why are we seeing surveillance camera evidence coming from major companies, small businesses, and government agencies recorded at low quality, with grainy video resolutions?”
I answered by agreeing that yes, many existing surveillance systems produce video image quality that is far below the potential of security camera technology available today. Yes, I can record high resolution video on the iPhone in my pocket and we can take amazing video with home video cameras. The problem is not the available technology — high resolution technology video cameras and recording systems are available. As you’ll see, even standard definition cameras would work very nicely — if configured and implemented properly. The problem is most camera security systems are not setup properly from the beginning.
The problem is two-fold: 1) Getting the budgets approved to purchase quality cameras and enough quality video recording systems; 2) Making sure the existing DVR recording devices are not overloaded with too many incoming video signals.
Number one, improving budgets, is self explanatory, but let’s discuss number two…
A very important reason so many security systems are recording inferior video quality is not due to the quality of the cameras or the video signal they produce, but it is instead due to how that video signal is recorded. The DVR hard drive devices that capture and record the video are too often overloaded with multiple cameras. Six, eight, or even ten cameras may be routed for recording on one DVR, and in order to handle all of that simultaneous digital information, that DVR needs to compress and shrink the size of each of those camera angles before recording that security surveillance on its hard drive.
A standard definition camera captures quite good image quality, and the standard DVRs used to record video signals in the last few years are also quite good. If you can dedicate a DVR to recording just that one camera or two cameras, then you’ll likely receive quality video.
But, if that security camera video signal is recorded onto a hard drive along with seven other cameras, the quality and detail will suffer considerably. This has less to do with the individual quality of the camera and more to do with the method needed to compress and record the video images.
All who attended the class earned 1 hour of MCLE credit toward continuing education requirements of the California State Bar.