You do have rights and responsibilities. Mr. Krages is an attorney and has published a book on photographic law. In addition, he has a guide to what your rights are as a photographer/videographer.
Let me add that when law enforcement is concerned you should be extra cautious; cameras have been confiscated and recordings destroyed. Protect yourself first, make sure you are not interfering with a crime scene/investigation and protect your recording.
- Andrew Hudson at PhotoSecrets also has a free guide to photography and the law. Andrew does state that is not a lawyer and refers to Bert Krages for citation.
- Rannie at PhotoJunkie.ca has a Canadian view of photographic rights.
- Andrew Kantor has an 8 page Legal Rights of Photographers Guide that you can download.