Better Call Glew: Am I Allowed To Film The Police?
The short answer to your question is yes, in California you are allowed to film or audiotape police officers in their official duty, as long as you are in public and don't interfere with them. However, there are several dynamics you must be aware of. While you can lawfully film a police officer carrying out his or her duties in public, they are not fans of the limelight. If given the chance, a police officer will use the excuse of being concerned for "officer safety," to prevent you from filming.
To avoid this, give the officer some space! Keep a good ten yards--minimum--between yourself and the action. The more space you keep from the police, the less attention you will draw, and in turn, the police will have fewer real or fabricated concerns for "officer safety." Furthermore, do not violate any laws while filming. For example, do not block a public sidewalk or walk into a street while filming, or not only will your directorial debut come to an untimely end, but you could become the focus of some unwanted police scrutiny for any infractions they witness.
To put it simply, if you want to film the police, you are lawfully allowed to do so, if you follow the above guidelines. If you want to film the police, and not be harassed by the police for doing so, be the proverbial fly on the wall.
Send all your questions to Glew at firstname.lastname@example.org. Remember: Better Call Glew!