. >> raven abaroa, his first wife murdered. his second wife growing scare and playing detective on the internet. >> and it thought there's no way. there's no way. >> bottom line, i wasn't involved in the death of my wife. >> tonight, we take you back to the crime scene a stranger's going print and stray dna. was there a intrurder in the house? was the killer closer to home? a lot closer? >> never forgets about raven. >> a cold case of murder that "20/20" helped put back on the radar. the suspicions about raven. video taping himself. his obsession with knives. >> that's my new knife that i got for christmas. >> and a didn't's hunch that to solve a crime, you have to look in the victim's eyes, literally. >> exhume the body of janet abaroa. >> what secrets will the grave give up about a marriage gone sou south. >> sleeping with the enemy. here now, elizabeth vargas and david muir. >>> tonight, the stunning case thrust into the national spotlight, two wives, one dead and one alive. murder investigation that had reached a dead end u