(CNN)The US Marshals Service led a multiagency effort dubbed "Operation Dunder Mifflin" to verify the addresses of registered sex offenders living in the area of Scranton, Pennsylvania.
The operation was presumably named in honor of the hit sitcom "The Office," which takes place at a fictional paper company named Dunder Mifflin in Scranton.
Despite the operation's name, the mission was serious.
Between August 2 to September 17, US Marshals coordinated with the Scranton Police Department to verify the home addresses of 219 convicted and registered sex offenders living in the area, US Marshals said in a news release on Monday.
Of the offenders, 13 were found to be in violation of sex offender registration laws, nine were arrested and four are still being sought for violations, the release said.
Eight of the arrested offenders were men and one was a woman, all between 22 to 48 years old. The individuals were convicted of a range of crimes, including indecent assault, sexual abuse of children, statutory rape, corruption of minors, sexual abuse, and involuntary deviate sexual intercourse.
"This joint operation was successful in ensuring those required to register remain compliant and those who are in violation are brought before the court to answer for their non-compliance," Scranton Chief of Police Leonard A. Namiotka said in the release. "The cooperation between the Scranton Police Department and our law enforcement partners is paramount in making our community safe for all citizens."
Authorities are still searching for four offenders, all men from Scranton wanted on outstanding warrants.
Operation Dunder Mifflin was supported by Pennsylvania State Police Megan's Law Section, which requires authorities to provide information to the public on registered sex offenders living, working, or studying in the state.
The law was put in place following the 1994 slaying of 7-year-old Megan Kanka, whose sexual assault and death led to a nationwide movement to protect children from sexual predators.
The 2006 Sex Offender Registration and Notification Act requires sex offenders to register with the National Sex Offender Registry and update their registration when they travel or move.
The US Marshals did not reply to CNN's request for comment.