negative. she s still your mother. it s still my wife. reporter: perhaps he understood the human heart after all. it took a year or so, but mary ann s ardor began to cool. the interest she had in being chased, that period rubbed off. after a period of time, it was she was certainly still passionately being chased by yanos. reporter: archie had a pension, savings, life insurance. mary ann was almost 50. did she worry also that yanos was too young for her, that maybe his feelings would change? eventually, mary ann decides, you know what? this is stressful. i kind of miss my life. i don t have the security that i had. mary ann decides, i want to move back home. reporter: archie welcomed her back. forgiving as always. no resentment, no anger? he didn t show any. reporter: how is that possible? that was my dad. reporter: across town in long beach, yanos wasn t so forgiving. he was fuming. yanos truly loved her. loved boring on obsession. unfortunately, it takes two peo
kind of made me question the whole system. reporter: the cops were sure yanos killed archie. gary was doubly sure. he still is hoofing around, breathing air and has all the freedoms that you and i have. didn t seem right. reporter: perhaps not. but the cops were simply stuck.
mother rushed to his side, they knew, both of them, without a shadow of a doubt, who did it. she immediately started saying, oh, my god, i m sorry, i can t believe he did it. i m so sorry. i m so sorry. reporter: mary ann met with the cops and told them. yanos did it.
something you can do. if nothing else, an opportunity to look at the evidence anew. 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 these murders occur, behaviors start to fall apart. you see the behavior of the 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 was frankly a little bored with archie. he loved her unreservedly. she knew that. but passion, excitement, not so much. she was a vibrant woman still and attractive. but 47 and in need of something. and then there he was, yanos. she met him at a local club. he was just 32, 25 years younger than archie. he was everything archie wasn t.
killing yourself in the front yard, you don t need to bring the gun into the house. you don t need to have an extra magazine with you. i believe that something much more sinister was going to happen that day. reporter: in fact, nothing happened. yanos went home. but he came back here to mary ann s house a few days later. it was on the friday before the murder. he met with mary ann alone. and had an epiphany. it was something he referred to in one of the conversations the police recorded between yanos and mary ann. i left friday. it never clicked until i came