While costumed kids tramped through Tampa looking for treats, Tampa police officers were in uniform knocking on doors for something far scarier.

"As part of our unit, it's probably our biggest day of the year to focus on children's safety," said Detective John Guzina.

Guzina sent out teams of officers to check up on over 240 sexual predators and offenders.

"Essentially our worst of the worst," Guzina said.

There are 850 sex offenders and predators that live in Tampa, according to Guzina. The names officers were checking in on Monday are predators and offenders who are either on probation or community control.

"They know we're coming. We tell them we're coming," Guzina said.

Officers checked IDs and made sure all information was up to date. They also made sure they weren't trying to encourage kids to come to the door.

"They know not to decorate, not to entice. There are probationary restrictions against that," Guzina said.