an nbc news consultant on other stories, loves them. especially the riddles of cases gone cold. he called a regular partner, a veteran detective jim wallace. >> in almost every case there's something you can do. if nothing else, an opportunity to look at the evidence anew. you see if anything was missed. >> reporter: wallace and lewin began by digging into the love triangle. by re-interviewing mary ann, asking about her relationship with both archie and yanos. and about the events that preceded the murder. >> typically, when t murders occur, behaviors start to fall apart. you see the behavior othe murderer become more and more aggressive and the murder occurs. >> reporter: so to the beginning, which was, of course, the love story or the betrayal, call it what you will. mary ann as they discovered was frankly a little bored with archie, but he loved her unreservedly. she knew that. but passion, excitement, not so much.