I have seen these too and although I'm certain there are bad interviewers out there, I have to say I gained a lot of respect for the detectives who conduct those interviews. They are much better than I could ever be at remaining dispassionate, curious, and above all, extremely patient.

The bottom line is that these interviews are all recorded and the police are well aware that if they make a misstep and if the defense has a competent lawyer, they may inadvertently set a thief, killer, or rapist free if they are not extremely careful in their questioning and processes.