AURORA, Ill. (CBS) — A 26-year-old Aurora woman is suing a 31-year-old Far Northwest Side man, after she says he sexually assaulted her after she met him on a dating Web site.

As WBBM Newsradio’s Mike Krauser reports, Thomas Januszewski, of the 3600 block of North Pontiac Avenue in the Irving Woods neighborhood, is already charged with aggravated criminal sexual assault.

LISTEN: WBBM Newsradio’s Mike Krauser reports

Januszewski and the victim, a 26-year-old woman, met on the dating Web site Plenty of Fish and began talking with each other on the phone, according to Aurora police Sgt. Matt Thomas.

At one point, they agreed he would spend a night at the woman’s home in Aurora, Thomas said. The woman’s lawsuit says she invited him to stay over after they agreed to meet in person and their conversation continued late into the night.

Both “agreed that nothing would happen” when he stayed over, according to the suit.

But police and the woman say when they woke up on the morning of Feb. 7, Januszewski allegedly sexually assaulted her, and then left.

The suit claims Januszewski forcibly removed the woman’s clothes and sexually violated her.

On top of that, Januszewski never disclosed he was a registered sex offender, according to the lawsuit.

Januszewski is listed on the Illinois State Sex Offender Registry for an earlier conviction in Utah, in which he solicited a 17-year-old when he was 25.

“She’s trusting, there’s no doubt about it, but they had a lot of conversations, a lot of correspondence,” the woman’s attorney, Jeffrey Deutschman said Wednesday. “She was careful, I think.”

Aurora police arrested Januszewski March 23 after collecting evidence and interviewing the suspect, Thomas said.

He was initially ordered held on $75,000 bond, which he later posted. He is next scheduled to appear in court in Wheaton Monday.

The three-count civil lawsuit against him claims intentional infliction of emotional distress, violations of the Illinois Gender Violence Act and battery. It seeks at least $50,000 in damages.

Aurora police continue to investigate.

The Sun-Times Media Wire contributed to this report.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)