both crimes. >> we were able to identify one suspect in the case and he's our prime suspect, matthew mullered in either case. we wanted to hear from muller himself. his attorney did not want muller to do an interview. however, muller agreed to see a visitor. "dateline" associate producer kayla ward spent 30 minutes talking with muller in jail through glass on the phone. no cameras, no recordings, no note taking allowed. >> what's his answer as to whether or not he's guilty of the crimes he's accused of? >> he wouldn't deny anything, but he wouldn't say he was guilty of anything. >> she asked him about samantha. >> recently interviewed a woman and her case matches the other cases. he couldn't believe that i was bringing this up. sexually assaulted and then you're brave and it's used against you by the police? tears in his eyes. he was very emotional about it. >> putting on a show? >> he might have been putting on a show. he's very smart. he wanted to be very clear that the last six years of his life have been spent in depression. he's had a few suicide attempts. he said, you know, he's in ja