Know Your Rights Photographers Guide 2011: For private citizens (investigators).
ACLU Know Your Rights As A Photographer:
When in public spaces where you are lawfully present you have the right to photograph anything that is in plain view. That includes pictures of federal buildings, transportation facilities, and police. Such photography is a form of public oversight over the government and is important in a free society.
When you are on private property, the property owner may set rules about the taking of photographs. If you disobey the property owner's rules, they can order you off their property (and have you arrested for trespassing if you do not comply).
Police officers may not generally confiscate or demand to view your photographs or video without a warrant. If you are arrested, the contents of your phone may be scrutinized by the police, although their constitutional power to do so remains unsettled. In addition, it is possible that courts may approve the seizure of a camera in some circumstances if police have a reasonable, good-faith belief that it contains evidence of a crime by someone other than the police themselves (it is unsettled whether they still need a warrant to view them).
Police may not delete your photographs or video under any circumstances.
Police officers may legitimately order citizens to cease activities that are truly interfering with legitimate law enforcement operations.
Professional officers, however, realize that such operations are subject to public scrutiny, including by citizens photographing them.
Note that the right to photograph does not give you a right to break any other laws. For example, if you are trespassing to take photographs, you may still be charged with trespass.
If you are stopped or detained for taking photographs:
Always remain polite and never physically resist a police officer.
If stopped for photography, the right question to ask is, "am I free to go?" If the officer says no, then you are being detained, something that under the law an officer cannot do without reasonable suspicion that you have or are about to commit a crime or are in the process of doing so. Until you ask to leave, your being stopped is considered voluntary under the law and is legal.
If you are detained, politely ask what crime you are suspected of committing, and remind the officer that taking photographs is your right under the First Amendment and does not constitute reasonable suspicion of criminal activity.
Follow the link to read more about videotaping...
Link: http://www.aclu.org/free-speech/know-your-rights-photographers