Paul Hayden was the obsessive, psychotic ex-boyfriend of Helen Bryce. They met in medical school, but Helen broke up with him when his ex-girlfriend told her that he beat her up.
Season Two[]
Paul visited Smallville on business and tried to steal Helen away from Lex. He sabotaged her car, and then showed up to rescue her. He injured himself and blamed it on Lex. When she rejected him, he beat her to within an inch of her life. He killed the security man Lex hired to follow him, so Lex tracked him down and very nearly killed him, but let him plead not guilty by reason of temporary insanity. Lex didn't fight the plea.
Paul is presumably incarcerated.