I've just watched this episode for the very first time and was thoroughly enjoying it until the part regarding the fingerprints. The killer touched the picture with his left hand leaving a left thumb print and the glasses with his right hand leaving a right thumb print!!!! No persons 2 prints are the same and, as this was supposed to be the way the killer was caught, I was very disappointed. I'm looking for a job, can I be your continuity girl? You obviously need one.