I know it can make you feel good, so -- a lot of times, i can't sleep at night. >> reporter: an autopsy showed lauren phelps was stabbed 123 times. new court documents show police say phelps was "obsessed" with the movie "american psycho," and that his private instagram shows him dressed as the main character, a serial killer. and according to court documents, a friend told police that phelps "expressed interest in what it would be like to kill someone." bayer, the makers of coricidin, tells abc news, "there is no evidence to suggest that coricidin is associated with violent behavior." >> this...