A suspect in police custody agrees to an interview. He answers some of the officers' questions, then says, "Maybe I should talk to a lawyer." The officers ask the suspect whether he's requesting a lawyer; the suspect says no. After a short break and the officers reminding the suspect of his rights, the suspect continues to talk. He eventually asks to have a lawyer present before saying anything else.
Are the suspect's statements up until the clear request for a lawyer admissible in court?
The U.S. Supreme Court considered facts much like these in a case called Davis v. U.S. (512 U.S. 453 (1994).) The Court noted that if a suspect invokes the right to counsel at any time, the police must at once stop the questioning until a lawyer is present. (A suspect can also invoke the right to remain silent—see Is post-arrest silence enough to stop police questioning?) But the Court also said that, after a suspect waives the Miranda rights, officers may continue asking questions until the suspect makes a clear request for a lawyer.
If the comment is ambiguous—if a reasonable officer would interpret it as a potential request for a lawyer—then the police can continue interrogating. The suspect must "actually" request an attorney to end matters. In other words, the suspect must say something that is clear enough for a reasonable officer to interpret it as a request for a lawyer.
(To learn about officers persisting with questions, including the difference between the suspect invoking the right to silence and the right to counsel, see Police Questioning After the Suspect Claims Miranda.)
In the Davis case, the suspect argued that what he said after "Maybe I should talk to a lawyer" should be suppressed. But the Supreme Court sided with the prosecution, finding no reason to disagree with the lower court's determination that the "maybe" statement wasn't a request for counsel.
The Court even went a step further, holding that officers don't have to try to clarify whether a suspect who has made an ambiguous statement is requesting a lawyer. So, even though it might have been "good police practice for the interviewing officers" to ask the suspect whether he was asking for an attorney, they didn't have to do so.
The Supreme Court has the final say on the federal Constitution, but states may read their own constitutions to provide defendants more rights. That means that the law can vary somewhat depending on where your case is. Differences in the law make for one of many reasons to talk to a knowledgeable criminal defense attorney if you've been arrested.
For further information on police interrogations, see What's the best way to assert my right to remain silent if I am being questioned by the police? And to learn about your rights in different kinds of police encounters, see Talking to the Police When You're Not in Custody.)