That's none other than Andrew Cunanan, the charismatic killer who in 1997 gunned down Gianni Versace on the front steps of his house in Miami, Florida. He allegedly went on a killing spree prior to killing Versace. About a week later, he committed suicide on a houseboat before police could apprehend him. That was a highly publicized manhunt.
Jeffrey Dahmer's neighbors referred to him as a "nice man." Meanwhile, he was chopping up body parts and eating them for a midnight snack.