The U.S. Marshals Office now has a sex-offender investigation unit and part of its job is to do compliance checks.
Rogers County, Okla., has around 150 registered sex offenders.
The sheriff's office and the U.S. Marshals went door to door this week, to make sure those offenders were following the law.
And they were ready to take action against those who aren't.
Two deputies, Sheriff Scott Walton and a U.S. Marshal allowed News On 6 to ride along during their recent compliance check.
One sex offender had a warrant out for his arrest, so he was handcuffed and taken to jail, but for most, this is just a routine check to make sure they are living where they claim.
Deputies didn't have to go far for their second check. It was right next door.
Deputy: "Hello, with the Rogers County Sheriff's Office, Adam here?"
Resident: "I don't know actually."
Sheriff: "Any idea where he went?"
Resident: "Probably Collinsville, to his sister's house."
Knowing where sex offenders are is a big issue with the public because they want to feel safe.
"The thing we're most concerned with -- are they attempting to find a new victim? So we try to at least protect the public on that," U.S. Marshal Will Kinnebrew said.
The offender living here was complying with address and employment both.
Deputy: "We just want to make sure he's doing what he's supposed to."
Resident: "You want to see his room?"
Deputy: "Yes, I would if that's fine with you."
A lot of the offenders are following the law. Those are not the people law enforcement is after.
"The design of this program is not to harass anybody being complaint or trying to do their best and obey the law and get their life back together," Walton said.
However, the person who said he was living in a Rogers County trailer, had moved out at least 10 days earlier, but not re-registered with the sheriff's office.
Failing to register is a felony.
The Marshals said they will gather up their evidence from this week's compliance check and alert the district attorney to those who are skirting the law.
To check the sex offender registry in your Oklahoma county, go to this government website, and choose your county in the drop-down menu.