My daughter is attending a citizen police academy. They discussed the challenges that police cameras (body, squad car, interview rooms, traffic monitoring, etc.) present — and these related, in part, to the objectives of having such cameras.
1) When an officer is apprehending a suspect, a video of the sequence covers a topic that is very likely to be raised in court (in the U.S. where fairly specific procedures need to be followed during an arrest.) Evidence related to this has to follow very specific rules to be admissible. An example of this concept is in the Fort Collins Colorado police FAQ where they provide some specifics. This process requires managed documentation trails by qualified experts to assure the evidence can be used. There are real expenses here beyond just having a camera and streaming/or transferring the sequences to the web. Web storage has been created that is designed to facilitate this management challenge. Note that even if the prosecution does not wish to use this material, the defense may do so, and if it is not managed correctly, seek that charges be dismissed. (For culture’s where defendants are not innocent until proven guilty and/or there is not a body of case or statutory defendants rights this may sound odd, but in the U.S. it is possible for a blatantly guilty perpetrator to have charges against him dropped due to a failure to respect his rights.)
2) There are situations where a police officer is suspected of criminal actions. For real time situations (like those in the news recently), the same defendants rights need to be respected for the officer(s) involved. Again close management is needed.
Note that in these cases, there are clear criminal activities that the police suspect at the time when the video is captured, and managing the ‘trail of evidence’ is a well defined activity with a cost and benefit that is not present without the cameras.
The vast majority of recorded data does not require the chain-of-evidence treatment. If a proper request for specific data not associated with an arrest results in data that is used in court, it is most likely to be by a defendant, and the prosecutor is unlikely to challenge the validity of the data since it deprecates their own system.
Of course there are other potential uses of the data. It might contain information relevant to a divorce actions (the couple in the car stopped for the ticket – one’s spouse wants to know why the other person was in the car); or the images of bystanders at a site might impact the apparent privacy of such persons. (Although in general no right of privacy is recognized in the U.S. for persons in public.)
The Seattle police are putting some video on YouTube, after applying automated redaction software to protect the privacy of individuals captured in the frame. Just the presence of the video cameras can reduce both use of force and citizen complaints.
There are clearly situations where either the police, or the citizens involved, or both would find a video recording to be of value, even if it did not meet evidentiary rules. Of course the concern related to such rules is the potential for in-appropriate editing of the video to transform it from an “objective” witness to bias it in one direction or another.
We have the technology— should we use it? An opinion piece by Jay Stanley in SSIT’s Technology and Society journal outlines some of these issues in more detail.