LOS ANGELES (CBSLA.com)  —  Officials call it “Operation Boo.”

State agencies work at keeping kids safe on Halloween night as they go door-to-door in search of candy.

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Agencies are keeping a watchful eye on sex offenders who preyed on children.

CBS2’s Jennifer Kastner went along as the operation was in full force.

“We don’t park in front of the house when we’re in raid gear,” said Parole Officer John Bent.

When these state parole agents approached their first Los Angeles home Saturday night, the front of the home looked to be compliant.

No Halloween decorations or candy outside the child sex offender’s place were visible.

But after a few minutes inside, the man was escorted out in handcuffs. Kastner asked Bent what was found inside the home warranting the man’s arrest?

“Well, they went through the room and searched it and found a parole violation,”Bent said.

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Agents can’t specify what that violation was but it could’ve been something like having pornography or alcohol.

House calls like these are common during the operation — all making sure child sex offender parolees are staying out of trouble.

So that families with trick-or-treaters can feel safe — even with a registered sex offender’s apartment a few feet away.

“We have pedophiles that have numerous victims. We have some that have one,” said Bent.

At headquarters — south of downtown —  a line has formed of homeless child sex offenders. They are required to spend much of the evening on site being supervised.

They’re required to wear ankle monitors that feature a GPS signal that can be picked up on an agent’s phone and computer

“It’s pretty accurate. We’re able to find these guys where they’re at, what their location is you know within minutes,” said parolee officer Ray Rodriguez.

The agengts Kastner spoke to admit it’s not easy dealing with people who have been convicted of something so heinous, but now it’s about getting their lives back on track.

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“If we focus on the past we’d never get anything done positive,”  Bent said, “We’ve got to try to move forward and try to keep them out of custody.”