It's actually the inverse: They suspect the individual but have no other recourse but to suggest to the suspect that they want to rule him out. It's akin to wh

It's actually the inverse: They suspect the individual but have no other recourse but to suggest to the suspect that they want to rule him out. It's akin to when police ask, "Do you know why I pulled you over?" The question is open-ended and if the driver admits to any other wrong-doing, other than the reason for the stop, that's now introduces reasonable suspicion (by the act of admission) to other crimes. Is it illegal? Technically, no. (Unless you go down the entrapment road.) Is it morally wrong? I think most people would agree that it is because the consequences aren't told the individual. (The informed consent argument.)