First, he bound and beat his girlfriend, a 43-year-old librarian. Then he went after her teenaged daughter - warning her, 'Scream and I will kill you both' - before knocking her unconscious. When the teenager awoke, he proceeded to rape her. And in a final horrifying act of depravity, he forced the girl to watch as he slit her mother's throat. But the killing didn't stop there...Stephen Stanko was described as 'a perfect gentleman' who 'seemed so pleasant...and so normal.' But behind Stanko's mild-mannered appearance, round spectacles, and quiet intelligence was a coldblooded ex-convict who kept a grisly scrapbook on serial killers - and convinced everyone he was a nice guy - until he killed and killed again. A well-orchestrated manhunt caught up with Stanko, who tried to get away with his crimes by pleading insanity. But the jury saw through his ruse and the ruthless killer was sentenced to death. WATCH MOMMY DIE-Michael Benson     Follow and comment on Facebook-TRUE MURDER: The Most Shocking Killers in True Crime History   https://www.facebook.com/profile.php?id=100064697978510Check out TRUE MURDER PODCAST @ truemurderpodcast.com