Robert Knepper portrays T-Bag on Prison Break.

Do chicks really dig bad boys? This is a question that has mystified straight arrows for years. You call home, you send flowers, you even do windows -- and still she runs off and marries Kid Rock.

Last month, on the network press tour in Los Angeles, the question was put to Robert Knepper. He plays the creepiest dude on TV -- Theodore "T-Bag" Bagwell -- on the hit drama Prison Break (8 p.m. on Global and Fox).

All crazy eyes and rooster 'Do, T-Bag was so deranged last season he spooked even his nastiest fellow cons. When he got his hand chopped off by mob boss John Abruzzi (Peter Stormare) in the shocking season finale, T-Bag only seemed to get more dangerous. Last week, armed with a screwdriver, he forces a terrified veterinarian to re-attach his bloody left hand.

Knepper, who flew to Toronto last June along with Wentworth Miller (Michael Scofield) to help Global hype Prison Break at their annual June upfront, admitted at last month's Fox press tour party that he's been getting some extra love from the ladies.

"I've gotten some sweet letters from women who say, 'I want to rip that tight white T-shirt right off you,' " he said.

Knepper has played bad guys before and has noticed that there are always certain kinds of women who are attracted to danger dudes. He notes that real-life monsters like Charles Manson get mash notes in prison.

"They either want to fix you, or, if they can't fix you, they think they'll have a good time trying."

People just like watching characters who are exciting and dangerous, he says. Besides, "it's much harder to play a good guy, somebody who has to stick to the straight and narrow."

What he likes about T-Bag is that there's some dimension beyond the bad-ass exterior. T-Bag's psych report revealed chilling stories of abuse. Viewers can see where he's coming from and even feel sympathy for the character.

Knepper quotes his acting hero, Robert De Niro, for the final word on the subject: "I don't play bad guys, I play characters who make decisions that are different."