Movies and television shows commonly portray police officers arresting and handcuffing suspects, reading them their Miranda rights, and questioning them. But Miranda comes into play in more scenarios than this one. The Miranda warning requirement arises if the suspect is subject to any kind of "custodial interrogation."
(For situations in which the warning isn't necessary, see Exceptions to the Miranda Rule. And to learn about whether the government can use information it acquires in violation of Miranda, see When Police Violate the Miranda Rule.)
The term "custodial" refers to the suspect being in custody. It doesn't necessarily mean handcuffs. Rather, it means that the police have deprived the suspect of his or her freedom of action in any significant way. (See Is a traffic stop an "arrest" within the meaning of Miranda? )
"Interrogation" means questioning. This questioning can be in the form of an officer asking the suspect direct questions, or it can be comments or actions by the officer that the officer should know are likely to produce an incriminating reply. (For a detailed discussion of what kind of police behavior equals interrogation, see Do officers have to read the Miranda rights before talking to a suspect?)
So, when is someone subject to custodial interrogation per Miranda? Courts have generally used a "totality of the circumstances" test to figure this out. For this test, a court will look at a number of factors and focus on the "physical and psychological restraints" on the person's freedom during the interview. (U.S. v. Axsom, 289 F.3d 496 (8th Cir. 2002).)
Courts may consider several factors to determine whether an interrogation was custodial. Overall, they try to determine how intimidating, coercive, and compelling the environment was. The questions they weigh include:
When considering the above questions in order to determine whether someone was in custody, most courts use what's called a reasonable person standard. The central question, which the questions above get at, is whether a reasonable person in the same position as the suspect would have felt free to leave.
Example: A police officer contacts Matt about a burglary, and Matt agrees to meet the officer at the police station to talk about it. The officer doesn't initially give a Miranda warning, instead, he tells Matt he isn't under arrest. The officer says he thinks Matt is involved in the burglary and tells him the police have found Matt's fingerprints at the scene even though they really haven't. Five minutes into the interview, Matt confesses. The officer then gives a Miranda warning, and Matt confesses again. A half hour after he entered the station, Matt leaves. The interview wasn't custodial because Matt voluntarily went to the station, the officer told him he wasn't under arrest, and he left at the end. (Oregon v. Mathiason, 429 U.S. 492 (1977).)
Example: Police officers who are investigating reports of child pornography appear at Bess's job and tell her to stop working. They escort her to a conference room, where an officer tells her she isn't under arrest and that she'll "walk out of here when we're done." The officer doesn't give a Miranda warning. He questions her for over two hours in a generally calm tone. Bess makes incriminating statements during the interview. Although the interview took a long time and Bess didn't voluntarily walk to the conference room with the officers, she wasn't in custody because the interview was in a familiar place, she wasn't isolated from the outside world, and the police didn't pressure her to confess. The conversation was consensual and not coercive. (US v. Bassignani, 575 F. 3d 879 (9th Cir. 2009).)