Backstage after the show, however, she saw the real Alcala. "He was kind of a creepy guy," Jed Mills, the bachelor next to Alcala, said in 2010.

There were already four bodies to his name when he popped up on national TV, smiling with perfect hair.

Rodney Alcala, one of the most infamous serial killers in U. history, would eventually be arrested and sentenced to death in 1980 for the murder of 12-year-old Robin Samsoe.

Please welcome Rodney Alcala." After the three bachelors were announced, the young woman who would choose one of them for a date began asking questions. "I am kind of bending toward the other guy to get away from him, and I don't know if I did that consciously. "And he was very obnoxious and creepy -- he became very unlikable and rude and imposing as though he was trying to intimidate. CNN asked noted crime profiler Pat Brown to analyze Alcala's appearance on "The Dating Game." "He was aware that he could say things that were considered sexy and funny and the girl would like that," Brown told CNN.

But thinking back on that, I probably did." Alcala was able to charm Cheryl Bradshaw from the other side of the "Dating Game" wall. "He watched the game and he gave those answers and he won, so he learned some tricks.

Here is a man portraying himself as a desirable young man when he is a violent sexual predator of children." Alcala's real identity revealed itself off the stage when he was with the other bachelors, Brown believes.

"He is showing his psychopathic personality in the green room," she said. Those were his enemies, and he had to beat them to get the girl and he wanted to win. This guy was going on the show to prove how special and wonderful he was.

Nobody at the time knew the man with the wavy long hair and toothy grin was an apparent psychopath -- an unstable, antisocial personality.

That includes Mills, a veteran television and film actor, whose only encounter with Alcala was when both of them appeared on "The Dating Game." "That's when I became part of a nightmare, and I didn't realize it was a nightmare until 32 years later," Mills said.

(He remains in prison in California.) While Alcala's body count is unknown, police estimate the now-73-year-old man killed at least dozens of women, with some counts running as high as 130 – and there are still over 100 photographs of unidentified women who may have been his victims.