Halloween is the one time many parents allow their kids to accept candy from strangers.  Quad City police are trying to make it as safe as possible.

Before kids go door-to-door, police agencies in Scott and Rock Island counties spent the past week knocking on the door of every one of the 635 registered sex offenders in the Quad Cities. This is the first time they all worked together, on both sides of the river.

"The timing was critical to make sure we're out there before Halloween," said Scott County Attorney Mike Walton.

Investigators say out of Scott County's 291 registered offenders, about 90 percent were compliant with their registration requirements.  32 were not where they're supposed to be and face charges.

In Rock Island County, they had a compliance rate of about 96 percent. Of the 344 sex offenders, 13 were not where they were supposed to be. As investigators follow up, they remind the public of the websites that pinpoint the location of each sex offender. They say to successfully track where offenders are living, they need help from the neighbors.     

"Because if we get a guy who says 'I'm compliant. I've lived there since I registered,' and you have neighbors who say 'I've seen him there only a few times or never,' it's actually relevant evidence for us to consider," according to Rock Island County State's Attorney Jeff Teronez.

Some of the responsibility falls on parents. Police recommend going out trick-or-treating with your child or knowing which houses they will visit.