“[Police] will lie to you about what crime they are actually investigating,” Duane writes in his book, “whether they regard you as a suspect, whether they plan to prosecute you, what evidence they have against you, whether your answers may help you, whether your statements are off the record, and whether the other witnesses have agreed to talk to them — even about what those witnesses have or have not said.”

When you talk to the police, it’s unlikely that your whole story will be relayed to the jury during a trial. Duane argues that federal and state rules of evidence make it much easier for prosecutors and the police to present damaging statements from an interrogation than for defense attorneys to present exculpatory information from the same interview. Say you vehemently deny shooting a man, explain that you’ve never owned a gun and don’t know how to shoot, and point out that you weren’t anywhere near the scene of the crime — but also admit, in passing, that, “Yeah, sure, I never liked the guy, but who did?” Even if all of that is true, Duane says, the jury might hear only the worst at trial, with an officer testifying, “He admitted to me that he never liked the guy.”

Duane says that while prosecutors can ask an officer who interviewed a defendant anything they want about the statement, hearsay rules can greatly limit what defense attorneys can elicit from the officer on cross-examination about other portions of the same statement.

Do these scenarios sound far-fetched? The data says otherwise. —NYTimes