The author studied normal CID work patterns for 6 months, observing 76 police interrogations involving 60 suspects. Beyond the standard set of procedures establishing the duration of custody, suspects' experiences of arrest, detention, and interviews varied considerably, primarily because of work organization, workload, and operating methods of the CID officers. All officers regarded interviewing as of central importance, often breaking the process into several steps as evidence emerged. Most officers preferred a friendly or business-like style which allowed them to change tactics convincingly and used the authoritarian approach only with aggressive subjects. The author discerned certain steps in the interview process: preparatory work, first reconaissance, serious questioning, interrogation, interviews in the presence of third parties, checking other offenses which might be considered, and taking the caution statement. In general, officers' statements about the interview were based on memory plus notes taken at the time. While a substantial number of interviews were held with individuals who were not in a normal mental state, it was impossible to judge whether the state of that suspect would have constituted sufficient grounds for excluding the statements obtained on the basis of involuntariness or oppression. Persuasive interviewing techniques, such as controlling the flow of information about options, influenced the suspect's decision to talk. The author concluded that rules governing voluntariness and oppression still have moral force, but that the right of silence is not a real option. Tables and photographs of the interrogation setting are provided.