Trick or treating? Do you know who is behind the door?

As thousands of kids across Central New York headed out to trick or treat, police warned parents to be careful who's door you knock on.

Parole officers were out in full force Monday night, making sure sex offenders stay in. Sex offenders are not allowed to have their homes decorated for Halloween or wear costumes. And they cannot have their porch light on, answer their door for children, or give out any candy. Parole Officials tell us one person was arrested on Halloween, in violation of parole.

Last year, Parole Officers made 185 stops in to sex offender's homes in Central New York and six arrests for parole violations. If an offender is found in violation of any of the rules, they can be taken into custody.

'We've arrested people before for having decorations up, being out past their curfew. Sometimes they have computers or access to computers and accounts such as facebook," said Parole Officer Jim Anderson.

Monday night, we rode along for three checks in Onondaga County. We found one minor violation, a porch railing was decorated with leaves and a string of lights. Officers instructed the offender to remove the decorations and when we went back to check, they were cleaned up.

Young children should always be accompanied by an adult or older, responsible child. Kids should also only go into homes where the lights are on and you know the homeowners.

Police also suggest that parents map out trick or treat routes ahead of time. You can check to see if any sex offenders live in your neighborhood by clicking here, and entering your zip code.