20 Famous Actors You Didn't Know Were on "Law & Order: SVU"

2. Jessica Walter

It's hard to imagine everyone's favorite verbally abusive mother from "Arrested Development" in any other role. In 2009 she appeared as a criminal attorney Petra Gilmartin and, shockingly, never had a single drink or yelled at Buster.

3. Hayden Pannetierre

Way back in 2001, a young Pannetierre starred as a girl named Ashley Black who was beaten and neglected by her parents. She reprised the role and made another appearance four years later in season 6 when the crew investigates a murder that resulted from teens hooking up online. What a dangerous world that Internet could be back in 2005.

4. Robin Williams

Williams appeared in season 9 as a sociopathic genius named Merritt Rook who would call fast food restaurants pretending to be a police officer and have the manager strip search employees. He gets the best of the police on multiple occasions and leads a protest against them with the help of Mo Rocca for some reason.

5. Henry Winkler

The Fonz got a little shady during season 3 of SVU. He played a murdering scam artist who committed identity theft in order to steal rich women's money. We can't blame the women; who could resist that face?

6. Amanda Seyfried

Before she became one of the biggest young stars in Hollywood, Seyfried played Tandi McCain, a girl who was attacked by a group of college bros. Of course the stories are never that simple and straight forward, as we end up delving into a bizarre relationship between Tandi and her stepfather.

7. Luke Perry

Season 10 started out with a bang. Luke Perry and Julie Bowen guest starred as a couple whose adopted son was out of control. Turns out that, not only is Perry's character a rapist, he raped his wife before marrying her. Yikes.

8. Rooney Mara

Early in her career, Mara appeared as a former overweight girl who flipped out and started attacking random overweight people to deal with her anxiety. She caught quite a bit of negative press when she said in an interview that her guest spot on the show was "Awful, so stupid." Probably not a good idea to diss SVU since it's been on for just a shade under 400 years.

9. Bradley Cooper

Before winning the hearts of America in "Silver Linings Playbook," Cooper was a defense attorney who, in season 6, defended Alfred Molina's character against charges of rape with the defense of severe Asperger syndrome. Nice try Bradley, but that's the oldest trick in the rape defense book.

10. John Ritter

In one of his finest performances, the late Ritter played Dr. Richard Manning during season 3. He is arrogant and maniacal as he is suspected of murdering his pregnant wife. Even if you aren't a fan of the show, this episode is worth watching just for his brilliant performance alone.

11. Martin Short

In season 6, Martin Short portrayed a psychic named Sebastian Ballentine who claimed to have knowledge and information on the disappearance of an 18-year old girl who has captured the attention of the city. Of course, this one takes a crazy twist and it turns out Ballentine isn't very psychic, just an insane murderer. That makes it much easier to know where the body is located, doesn't it?

12. Jerry Lewis

Lewis is almost unrecognizable during the first half of his episode, as he portrayed Detective Munch's uncle in season 8. He is completely crazy and off his medication, which leads to him interfering in an investigation and taking justice into his own hands. Just like Batman, only fatter.

13. James Van Der Beek

If you're looking for creepy performances, look no further than Van Der Beek's SVU episode. In 2012, he played Sean Albert, a man who pretended to be the biological father of sperm donor babies in order to seduce them and have sex with them. Go ahead and read that sentence again if you need to, lord knows I did.

14. Ludacris

Luda delivered a solid performance in the season 8 finale as Darius Parker, who is on trial for the rape and murder of a young woman. He defends himself in court and exposes secrets on just about every cast member in the show in order to be declared innocent. He did, however, piss off Ice-T, which is worse than any criminal conviction in my book.

15. Bob Saget

Season 8 was filled with great guest appearances, including Saget, who appeared as Glenn Cheales. Cheales found success in controversial technologies, only to see them turn on him and result in him becoming a suspect in murder. When will we learn the message of "The Terminator"? Don't trust technology, people.

16. Elizabeth Banks

Way back in season 3, Elizabeth Banks guest starred opposite Mark-Paul Gosselaar as a couple who were working in the adult film industry to pay for their daughter's medical bills. I would have checked on Medicaid, but to each their own, I suppose.

17. Carol Burnett

In season 10, the legendary Carol Burnett delivered a masterful performance as a ridiculously wealthy woman whose underling takes care of all of her problems, including murder. Unfortunately, Matthew Lillard plays her young assistant, but don't let that detract you from checking out her magnificent appearance.

18. Jennifer Love Hewitt

The love of my life, Jennifer Love Hewitt, appeared in the premiere of season 12 where she had been stalked by a rapist for decades and, as a result, was afraid to leave her home. I just want to state for the record that if any of you ever hurt J-Love, I will personally pay for the best attorney to send you to jail for as long as possible. She's an angel and a national treasure.

19. Ty Burrell

Season 3 was packed with so many stars before they were stars. Episode 15 featured the "Modern Family" favorite as Alan Messinger, an attorney for a death-row convict who attacks Stabler and Dr. Huang. Sorry, Phil Dunphy, we love you but not enough to allow anyone to attack Dr. Huang.