Here in my town, two people were murdered. The police arrested 3 kids ( young teenagers ) as witnesses...they did not lawyer up, and after 18 hours of questioning, they confessed to the murder. right afterward, they recanted and stated they were coersed into confessing. the kids spent 6 months in jail awaiting trial. cops never looked for anyone else. they had the criminals. or so they thought. just before trial, they arrested 2 people in another state that confessed to the murder. the kids were just witnesses to begin with. if they had lawyered up right at the start, they would not have spent a day in jail, and the investigation would have continued. and for the record, there was no tape recording or video recording of the questioniing, just the cops word. The police have a job to do, they are not your friends.
People do odd things under stress.
Obviously, at some point (or at all points) they lied to the cops.