First described is a 4-week experiment conducted in Kent County's Dartford Police Station to test the feasibility of tape recording arrestees. A discussion of the results covers the following: technical observations relating to the recording, playback, and transcription of tapes; the effect on police and suspects; attitudes of solicitors. It concludes that if recording is to be established, it should be video and confined to the taking and read-back of statements under caution. The paper then describes 2-year field trials that began in September 1983 where six sites tape recorded all interrogation for all indictable and some summary matters. Services offered by the Home Office Tape Laboratory are outlined, as are their suggestions regarding audio and video tape recording. Issues considered include tape enhancement, the need for copies, written transcripts, tape authentication, voice identification, and interview rooms. Based on observations of the Metropolitan (London) Police Technical Support Unit, the paper explores audio and video recording outside the controlled interview room. Also discussed are tape recording experiments conducted by the police in Scotland during 1980.