Determining “Miranda custody” is an objective inquiry based on the totality of circumstances. Brown v. State, 2017 Md. LEXIS 154 (March 27, 2017):
A determination of whether an individual is in Miranda custody is an objective inquiry based on the totality of the circumstances. … In deciding whether an individual is in custody for purposes of Miranda, we must determine, in light of “the objective circumstances of the interrogation,” …, whether a “reasonable person [would] have felt he or she was not at liberty to terminate the interrogation and leave.” … Thus, we determine an individual’s freedom of movement objectively in light of the totality of circumstances of the situation, taken as a whole. … Facts often relevant to our analysis include:
when and where [the interrogation] occurred, how long it lasted, how many police were present, what the officers and the defendant said and did, the presence of actual physical restraint on the defendant or things equivalent to actual restraint such as drawn weapons or a guard stationed at the door, and whether the defendant was being questioned as a suspect or as a witness. Facts pertaining to events before the interrogation are also relevant, especially how the defendant got to the place of questioning whether he came completely on his own, in response to a police request or escorted by police officers. Finally, what happened after the interrogation whether the defendant left freely, was detained or arrested may assist the court in determining whether the defendant, as a reasonable person, would have felt free to break off the questioning.