andrea canning (voiceover): brook baker. related. so you've got this connection now-- yes. andrea canning: --between the roommate and brook. andrea canning (voiceover): detectives already knew brian's roommate from their earlier investigation. he had dated brook and provided a dna sample, which didn't match 137f. they had spoken to him enough to know brook had visited his home many times and met his roommates, which meant brian jones knew brook, too. so they asked him point blank, had he ever had sex with brook baker? bob dunham: he even said that i never dated her. i never had sex with her at any time. and after those statements, he was definitely somebody we were going to get dna from. did he willingly give you that dna? yes. yes. andrea canning (voiceover): brian jones not only provided blood and hair samples, he handed over the clothes and shoes he wore that saturday and allowed investigators to search his car and house. his willingness to cooperate might have made jones appear less suspicious, but something on one of hi