his name was ynobe matthews. >> he mentioned that he did attend this party. . >> reporter: like many people who'd attended, ynobe agreed to an interview, his down at the police department. >> he was friendly, and cooperative, said carolyn had left the party before he had. he later left the party. went with another female that was at the party over to a convenience store that was close by and bought some cigarettes. >> reporter: ynobe gave the detective a dna sample, and supplied the clothes he'd been wearing. to verify his alibi, the detective pulled surveillance video from the convenience store and noticed something. >> the clothing that he was actually wearing was different than what he had just told us. why is he not telling us the truth? >> reporter: ynobe claimed he'd simply forgotten, and then handed the detective the proper clothing. no forensic evidence found on the clothes connected him to the crime scene. >> so this wasn't your big moment. >> no. it wasn't. >> reporter: the big moment did come though, just a few nights later when the pieces of this p