A convicted child sex offender was back in court Monday. Investigators say she was caught babysitting young children.

A sex offender registration specialist says Roberta Bever broke a law that a lot of people aren't even aware of. It essentially says anyone who is convicted of a sex crime against a child cannot work or volunteer with children under 16. But, it's up to you to know if your kids are in fact around sex offenders.

The Boyceville police chief arrested Bever on Friday at her Dunn County home. Bever was convicted of first degree sexual assault of a child in 1998. This time she was arrested for working with children under 16 and not reporting her new employment as a babysitter—both felonies.

"It's just a case of someone following their gut and taking action," says Jodi Voegeli, a sex offender registration specialist with the Wisconsin Department of Corrections.

Voegeli says a teacher noticed that Bever, using a different last name, was listed as the babysitter for a five-year-old boy and a six-year-old boy. That teacher told the principal. The principal called the Boyceville police chief and the chief called Voegeli.

"Obviously, with Ms. Bever having an offense against a minor, her babysitting two small children could put those children at risk so we want to protect potential victims," Voegeli says.

Voegeli says she suspects there are other registered child sex offenders out there who are breaking the same law. She says that's why it's so important you check the registry. But, she says you also have to be proactive.

"The fact is the registry and GPS and all this comes in after someone's been assaulted and I prefer families and neighborhoods work together to prevent sexual assaults by empowering kids to prevent it from happening in the first place,” Voegeli says.

Voegeli says that means talking with your kids about what it's like to feel uncomfortable and about when secrets are good and bad. She says it's important children know how to say "no."

Andrew Maki is the prosecutor assigned to Bever's case. He says he expects to file formal charges between now and her next court appearance later this month. In court, Maki said Bever said she didn't know she was violating the law. We could not reach Bever for comment.

If you think someone might be violating the "crimes against children law," you should call toll free 1-877-234-0085

CLICK HERE TO GO TO THE SEX OFFENDER REGISTRY