The New Jersey State Police is urging parents to check the state’s sex offender registry before taking their children out trick-or-treating this Halloween.

The agency says that there are about 3,800 registered sex offenders living in New Jersey.

A map of registered sex offenders can be found at the state police website. Parents can also register to see if a sex offender moves within a specific radius of any address entered.

“You’ve provided your children with flashlights or glow sticks, and you’re going to check their candy before they eat it. But before they walk out the door, make sure you know who lives in the neighborhoods where your kids are trick-or-treating,” a state police spokesperson said in a statement on Facebook.

State police say that any parent planning on trick-or-treating in a family or friend’s neighborhood should register their address beforehand to determine if there are any offenders living in the area.