>> reporter: so michael's brother confirmed the troubled young man ran with a shady crowd. investigators were all ears. >> reporter: does his association with the house, his back story, make him a person of interest to you? >> he's definitely a person of interest. >> reporter: the deputies kept michael at the station for nearly three hours but they didn't hold him that day. he gave them a number for his alibi witness, that friend he'd gone to see that morning. would he vouch for michael? >> another mystery. >> we had some blank checks in one of our offices that disappeared. >> and a new theory of the crime. >> we didn't know if they were in this together or what.