that's what alcala wanted. >> serial killers are predators and yes, they act like an animal that is trying to get his prey, and the rest of the time it's trying to blend in so we don't notice him. >> reporter: at least one person noticed something, bachelor number two, jed mills, still recalls how alcala seemed dark, slimy and obnoxious, treating others like objects until he wanted something. >> i'm called the banana, and i look really good. >> can you be a little more descriptive? >> peel me. >> reporter: investigators have long pursued alcala even before he appeared on "the dating ga game." he'd been convicted of kidnapping and raping a young girl. he was convicted twice in the killing of robin sanso. twice the case went to retrial before finally this latest conviction for her and four other murders. and over the years, investigators have raised many