First, how do you intend to record? Public activity on a public street should be fair game. IF you intend to record phone conversations, even if you are a participant there are some rules:
Sec. 52-570d. Action for illegal recording of private telephonic communications. (a) No person shall use any instrument, device or equipment to record an oral private telephonic communication unless the use of such instrument, device or equipment (1) is preceded by consent of all parties to the communication and such prior consent either is obtained in writing or is part of, and obtained at the start of, the recording, or (2) is preceded by verbal notification which is recorded at the begining and is part of the communication by the recording party, or (3) is accompanied by an automatic tone warning device which automatically produces a distinct signal that is repeated at intervals of approximately fifteen seconds during the communication while such instrument, device or equipment is in use.
FWIW, you may well have the right to (in some states you expressly do not) film them in their routine. You also have the right of way in a cross walk--but it sometimes not a good idea to challange a moving car from the crosswalk.
Eventually you will run across an officer who feels his/her safety is in jeopardy--a camera can look like a weapon these days, an in the way photog may be obstructing an investigation. After you dust yourself in such a situation, off don't forget to ask for your ID back.
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