committed. >> the da asked christie's family and friends to take a look. >> but when they actually saw the composite -- >> i did not see anybody i knew, i was like, this was a stranger. >> in october, 2017, the da made the composite public during a press conference. maybe somebody else would recognize the person in those images? >> there is no chance this could be a waste of our time. >> we got a lot of calls, some seemed hopeful at first. but ultimately, this led to nothing. >> oh, that is so frustrating! >> yes. this was kind of like we fought like it was our last, shot, our last thing we could do. >> the composite did not work. but it would not be their last shot. that is because, investigators working on an unrelated crime in california came upon another way of solving cold cases. >> police arresting a man they believe was the so-called golden state killer, discovered using dna. >> california detectives found their suspect after uploading