Chicago area sex offender accused of grooming missing Massachusetts girl

CHICAGO (CBS) -- A convicted sex offender from unincorporated Glenview, Illinois, has been arrested on multiple felony charges, accused of grooming and traveling to Boston over the last year to have sex with a 16-year-old girl.

Weston Opas, 42, was arrested on Thursday at his home, after Cook County Sheriff's deputies learned a missing child from the Boston area was staying at his home, and obtained a search warrant for the home. Court records show the victim is a 16-year-old girl, who will turn 17 later this month.

Sheriff's detectives had learned Opas had met the girl online through a gaming app, eventually messaging her on an encrypted platform, and then exchanging text messages. 

Sheriff Tom Dart told CBS 2's Tara Molina that Opas intentionally groomed her, ultimately traveling to Boston on more than one occasion to have sex with her. He eventually sent her a ticket to fly to Chicago, where he kept her in his home for the last few weeks.

"They'll start off innocently, and then they slowly build, and they build, and that's literally what happened here," Dart said of these types of grooming cases.

After the girl was reported missing, detectives learned she was staying with Opas.

After sheriff's deputies raided his home, they found the girl and placed her in the temporary care of the Illinois Department of Children and Family Services until her family arrived in Chicago to take custody.

Deputies also found Opas was in possession of a gun, ammunition, and body armor.

Opas has been charged with grooming, traveling to meet a child for the purpose of engaging in sex, unlawful use of a weapon by a felon, and failure to report a child in his home.

He has been ordered held in custody until his next court date on Nov. 16.

Opas was convicted of child pornography in Orange County, Florida, in 2004, and was required to register as a sex offender.

He also was arrested earlier this year for violating sex offender laws by showing up at a Glenview school on back-to-back days to drop off and pick up his own child at school. Sheriff's officials said he did not have any contact with other children at the school.

Within weeks of that arrest, Opas is accused of flying the teenage girl from Massachusetts to Chicago to stay with him.

"We've dealt with these type of cases for many years. Your conventional type of reasoning sort of goes out the window," Dart said. 

Molina: "This arrest means a lot to one young girl's family, but it means more, right? Tell me what bringing someone like this in means to all of Cook County."

Dart: "Before I was doing this, I was a prosecutor, I handled a lot of these type of cases back then, and I can tell you that historically, most of the people that were engaged with this horrible activity, it wasn't one-off; like, oh, it's just this one person. No. They're usually out there looking for multiple victims."

With Opas in custody, investigators have been working with law enforcement in the Boston area to determine if Opas was talking to or involved with any other children there.

The girl in this case has since returned to the Boston area with her family.