friend's, what did you have on? >> just regular jeans and a t-shirt and my red jacket. >> just blue jeans? >> yeah, blue jeans, nike shoes, a t-shirt underneath, and he had his red hoodie on. >> do you mind if we see your nikes? >> yeah, sure. >> reporter: chris wanted to help. he gave those nikes to investigators, as well as his clothes. he even gave a dna sample. and after his interview, chris' dad called up sergeant carpenter. >> he had told us in this phone call that l.j. had driven by the house, was threatening chris. >> reporter: so here's more information that this l.j. is a very real and threatening person. >> yes. >> reporter: detectives also spoke to chris and annie's friend spencer riddle. spencer said he was at the gym with his brother the night annie was killed. >> sometimes you just have got