COLUMBIA, SC – By law, sex offenders have legal access to your children in schools.

Our sister station, WSPA, investigated what legal access sex offenders have after one was discovered to be on a Greenville County field trip to Charleston.RELATED: Sex offender chaperoned elementary school field trip in Greenville Co.

Sex Offenders are split into two categories Tier II and Tier III.

Tier II covers most crimes that have intent to commit a sex crime, Tier III covers more egregious crimes that where someone has committed a sex crime. Judges can also deem someone a sexual predator, which is a title for habitual offenders. Only a handful of those are sentenced to live further than 1,000 feet from a school. There are a rare amount of cases where sex offenders are barred from being on school grounds at all.

But 7News learned Tier II and Tier III sex offenders are both allowed on school grounds, allowed to be chaperones, volunteers, or just attend events.

It is up to the school district to put procedures in place to check if volunteers or anyone at the school is a sex offender.

Tier II sex offenders are required to register with their local Sheriff’s Office twice a year. Tier III are required to register 4 times a year. Offering up their current address, phone number, employment, registered vehicle, and any social media pages.

If a sex offender wishes to attend a school for any reason, they are required to notify the sheriff’s office. The sheriff’s office is not required to notify the school that they have checked in.

You can check the sex offender registry, here. You can search in your geographical location for sex offenders in your area, you can also search for sex offenders near your child’s school or daycare.