Mariska Hargitay immediately knew she wanted a role on "Law & Order: SVU."

The 55-year-old actress recalled on Wednesday's episode of "The Late Show" with Stephen Colbert how she got "chills" when she read the first script ahead of her audition.

"I read the script and I just -- I knew in my gut that I had to do this role. I'd never been so excited about it," Hargitay, who plays Olivia Benson on the NBC series, told host Stephen Colbert.

"The thing that was interesting is that my agent called me, and he said, 'Maris, you know it's very dark subject matter. I don't think if it's your thing,'" she said.

"I read it and just, you know, chills. And I knew I had to do it."

Hargitay said she was "so excited and so sure" about "Law & Order: SVU" when she met series creator Dick Wolf for the first time.

She spoke to the producer again during a callback when she mistakenly assumed another actress was there for the same role.

"So, I walked in and I go, 'Listen, you're confused. Here's the deal, I'm pretty sure this is me. I'm pretty sure this has got my name written all over it. This is my part. I'm serious, we're past this, let's not even waste your time,'" the star recounted.

Reality TV World is now available on the all-new Google News app and website. Click here to visit our Google News page, and then click FOLLOW to add us as a news source!
"He laughed, and then we went to network and I got it. And I found out that the other girl was for another role, and she was in the pilot, too!" she said with a laugh.

"And we've become friends."

"Law & Order: SVU" debuted in September 1999 and was picked up for a 21st season in March.

Wolf had nothing but praise for Hargitay, now also an executive producer, in a press release at the time.

"As 'SVU' moves into its third decade, Mariska has become an iconic figure as a star, advocate and crusader for women," Wolf said. "Mariska is a delight as #1 on the call sheet and, to me, a true friend."

"I am deeply proud to be a part of this groundbreaking show," Hargitay added.

"The longevity and continued success of SVU is a testament not only to the show's powerful storytelling and ability to connect with viewers, but to its necessity. We have told important stories for 20 years, and we will continue to tell them."

"Law & Order: SVU" co-stars Ice-T, Kelli Giddish, Peter Scanavino and Philip Winchester.

Photo credit: Law & Order: SVU