preadmore, this is det. smith. >> we brought her in right away.tective and i sat down with her and interviewed her. >> reporter: her name was kerri carr. >> when i went to go leave i walked out and was trying to get in my car. >> ok. >> and he pulled out a knife. ok. a pocket knife. and then he goes, "this is the one i used on chelsea." >> she provided information that this ex-boyfriend of hers told her that, you know, he was at the party and that he left with chelsea, and that he ultimately ended up killing chelsea and dumping her body in the toledo area, in a cemetery. >> reporter: and kerri said he threatened to kill her, too. >> he like grabbed me by my shirt and he had a knife and he goes, "this is what i used with chelsea bruck." he didn't say her name exactly -- >> what did he say? i need to know exactly. >> he said, "i used it on chelsea, don't make me use it on you." >> you could tell that she was nervous, you know, real on edge. >> reporter: kerri said she lived in fear of her ex-boyfriend and she wanted him arrested right away. >> i wan