THORNTON, Ill. (CBS) — A restaurateur in south suburban Thornton welcomed children into his business – and even sponsored a Little League game.

But authorities said Tuesday that he is a convicted child sex offender – and now he’s on the run.

CBS 2’s Tim McNicholas dug into the past of the suspect – known in Thornton as Raul Castanada, but actually named Carmen Leato, according to authorities.

The Illinois sex offender registry said Leato sexually assaulted an 11-year-old girl in 1992, when he himself was 22.

Thornton police said he used the Raul Castanada name when he started two new businesses – Shelly’s Pancake House and Mangia Tutto restaurants. One of the restaurants was surrounded by police tape Tuesday after officers learned of the owner’s true identity.

The businesses are both new. The defendant, 49, opened Shelly’s about six months ago and Mangia Tutto only about two or thre weeks ago.

Police said last month, they started hearing reports that “Castanada” had been writing bad checks to kitchen supply companies. They investigated and discovered “Castanada’s” real identity.

“I mean, it’s really, really bad,” said Joyce Gill.

Gill said she has gone to Shelly’s twice with her young grandkids, and the restaurant even sponsored her grandson’s Little League.

“I’d like some closure and clearance as to make sure this never happens again with somebody else,” Gill said.

Police said they tried to arrest Leato about two weeks ago. But officers said due to bounced checks, he was already in hiding and they have not been able to find him.

Now, both of his restaurants are closed, and officers say the employees were fooled too – some are still waiting on paychecks.

“We never had any reason to delve into his background. It’s not something we just do with a business owner, so we never looked into his background,” said Thornton police Chief Glenn Beckman. “It’s disturbing that we opened our hearts for him and he was this monster.”

Officers believe Leato and his wife left town. Police say the couple has worked with other restaurants in the south suburbs, and they may have used others as a front to commit fraud.

Leato has a lengthy criminal history dating back to 1992 that includes convictions of theft, forgery, and sexual assault, police say.

“Something should be in place with the government here when a business comes into here to make sure that these people here are somebody that they could trust,” Gill said.

Chief Beckman said this will likely result in stronger background checks for Thornton business owners.

He said Leato was even able to get a temporary liquor license on the condition that he would finish the background check process. But Leato left town before finishing that process.

Police said Leato never lived in Thornton.

Thornton police said anyone who knows where the Leatos might be should call 911. Carmen Leato is considered to be armed and dangerous.

Anonymous tips can be provided to Thornton police at 708-877-4440.