Not even just to get a confession. Police can stop you on the street for no reason and lie to your face telling you that you are required to hand over your ID o

Not even just to get a confession. Police can stop you on the street for no reason and lie to your face telling you that you are required to hand over your ID or allow them to search you and if you refuse you'd be committing a crime and will go to jail. If you don't know your rights you can end up giving them permission to violate them. You can't even trust police to tell you when you're doing something illegal.