Amanda Righetti and Owain Yeoman Amanda Righetti and Owain Yeoman

Fans of The Mentalist love Wayne Rigsby, the towering, emotionally dyslexic detective played by Owain Yeoman. But as the hit CBS crime show nears the end of its third season, there's still very little known about the guy. We're about to find out why. In tonight's episode, "Like a Redheaded Stepchild," we meet Rigsby's dad — played by the great William Forsythe — a crass, abusive scum of an ex-con who may be connected to the murder of a prison guard. Bad Dad's rap sheet includes convictions for manslaughter and assault.

"It's a real eye-opener," Yeoman tells TV Guide Magazine. "You suddenly understand why Rigsby grew up and became a cop. He came from a really messed-up home life, the kind that can easily send a kid down the wrong path. Instead, he took a stand against his father and decided to do something good with his life, all the while keeping his past pretty much a secret. Now comes a chance for Rigsby to finally face the truth and admit, 'This is where I come from.' I feel very lucky to have this episode."

Rigsby is forced to grill his father about the murder case and their reunion eventually turns violent. "It's a wonderful epiphany, a real series-defining moment for my character," says Yeoman. "Rigsby comes away from it having grown a pair of balls." And he's ready to tell his ex-love Grace Van Pelt (Amanda Righetti) — who's about to wed an FBI agent — that he still has a thing for her.

"For three seasons we've watched Rigsby be a bit of a lapdog," Yeoman says. "It's part of his bumbling charm but, where love is concerned, it's also been his downfall. The confrontation with his dad forces him to take perspective and tell Van Pelt what's in his heart. It's time for Rigsby to say, 'I have to look after me now.'"

The Mentalist airs Thursdays at 10/9c on CBS.

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