I just returned from a forensic video and audio expert conference in Las Vegas, where there were participants from the FBI, U.S. Army, Pentagon, police stations, and corporate representatives too. I watched a video the FBI gave us called “Best Practices for the Installation of CCTV Recording Systems.”
The title does give off the impression that the video would be dry. I was pleasantly surprised that the video played like a CSI forensic investigation, with the narrator stopping to explain the various steps and important factors when setting up and utilizing CCTV security camera video systems.
The FBI Forensic Audio, Video, and Image Analysis Unit set out to teach viewers a few helpful techniques to capture the best quality video possible. I’ve highlighted the main points below, and trust me, I’ve seen bad video evidence exactly as the result of not following these suggestions.
Resolution and frame rate
- Have a high-resolution camera. Not a webcam, but an analog or digital camera with high-resolution options.
- Suggests minimum resolution of 480×640.
- Needs to have a “high enough” frame rate (the FBI doesn’t suggest a minimum, and I suggest 20 frames per second as a minimum these days, with 30 even better).
Camera position
- Make sure the camera is at the correct angle for clearest view.
- Make sure camera is focused correctly and captures the desirable depth of field.
- Camera should be as close to eye level as possible.
- Set up a camera so a sign or wall doesn’t obscure the view.
- Don’t point the camera towards a door where light blinds the view.
- Cameras should be setup to overlap each other, covering as much of the business as possible.
Lighting
- Is the camera setup properly to capture video in both day and night?
- Schedule lights to come on at night (adjusted for sunset) to capture night footage.
- Pay attention to how light changes in the store and add lights where they are needed to always capture a well-lit image.
Recording device – The DVR
- Set up the recorder to capture the best resolution possible, given space requirements on the hard drive. If multiple cameras are being recorded onto one DVR, the strain on the DVR can sometimes cause intermittent recording problems and the loss of data.
- When saving evidence for use in investigations and court, ALWAYS export the NATIVE file from the drive, it is always better resolution. In addition capture CD, DVD, or .AVI file.
- Write down the DVR brand name and model number to locate a NATIVE PLAYER online
At the end of the video I was glad to have this refresher. I didn’t learn anything particularly new about audio and video forensics, but it did help me categorize the topics and specific issues in my head. It’s always good to be organized. And it will probably help me teach my MCLE class on audio and video surveillance footage!
Here’s the links to the video, I found them on YouTube!
Best Practices for the Installation of CCTV Recording Systems Part 1 http://www.youtube.com/watch?v=TRPVG9inn5w
Best Practices for the Installation of CCTV Recording Systems Part 2
http://www.youtube.com/watch?v=gA7VSGmTYG4