Much of what is said about video evidence is true; primarily the ease with which video evidence can be altered. While it is possible to show if an older camcorder that uses magnetic tapes has had the tape altered, it is possible to circumvent those methods and make the tell tale signs invisible to detection. The main problem I see is that there currently isn’t a good way to ensure tampering with the recording device.
After some thought on this subject, it had occurred to me that the only way to get any credible video evidence is to secure the recording device. While this doesn’t prevent deception that may be used to fool a camera, it does make it so tampering with the recording device and original recording is not so easily accomplished, if it can be accomplished at all.
In order to gain any credibility with video evidence, here’s what I would propose:
I would first setup a PC within a lock box, similar to a small safe. This lock box would also be constructed so it could only be opened by personnel who have an established reputation of trust, and only opened where the entire process could be recorded and documented. Lloyds of London, or some similar establishment who’s credibility means everything to their business. The box would also have sensors to detect and record anytime the integrity of the box was compromised. The only interface that the end user would have to the PC is the video inputs, keyboard, mouse, HDMI, and either USB or Firewire.
For the PC, I would encrypt all data written to the hard drives so simply removing a drive and putting it into another PC would not work, as well as trying to put different drive into the PC and read from them. All video signals would be Hi-def and would be encrypted as well. This would help prevent someone from simply connecting an external video source and recording it. The software would allow for transfer and viewing of files, but would not allow any editing of files. Deletion would be possible, but all sectors used by the deleted file would be written over, much as a data shredding program does.
As mentioned, I would use encrypted, Hi-def cameras and enclose them in a similar case as the lock box for the PC. I would also use stereo cameras, which would help in determining where in the field of view the anomaly occurred, as well as making poorly conceived hoaxes easier to detect. While this does not prevent certain tricks to be visually played before the camera, it does make a host of fraudulent methods easier to detect, especially when employing more than one camera at a location.
It’s a fairly tall order, and no company I know of manufactures this type of equipment, but it is one way to ensure with a fair degree of certainty, that the video that is recorded is tamper free. True that it can be altered after downloading from the box, it makes doctoring the video still residing on the box highly improbable, if not impossible.
