When Jackson Mayor Frank Melton went looking for a top lawman for Mississippi’s crime-ridden capital city, he turned to someone who had arrested him.

Just months after the mayor was acquitted on criminal charges of busting up a ramshackle duplex he thought was a drug den, Melton on Friday named Hinds County Sheriff Malcolm McMillin the new chief of the Jackson Police Department.

This marks the first time in Mississippi that a sheriff will have a dual role as police chief, and the change is happening in Mississippi’s largest city and county.

McMillin replaces Shirlene Anderson, who was removed as chief by Melton on Wednesday.

It will be McMillin’s job to clean up the mess made by Melton’s micromanagement of the 409-person department that’s suffering from low morale and understaffing. The city of 184,000, has a crime rate nearly twice the national average.

It is a strange political marriage as McMillin’s office has twice arrested Melton — once after the city leader was charged with malicious mischief, burglary and carrying a gun on school property and again on a parole violation. Both men are strong-willed, so butting heads could be unavoidable.

Melton has gotten into legal trouble for unorthodox tactics of carrying guns and cruising the inner city in the police department’s mobile command center.

McMillin, 63, is a no-nonsense sheriff for 16 years and an actor in local theater. He recently won re-election with 60 percent of the vote. McMillin said the police department and the sheriff’s department will not merge and Melton will not control law enforcement.

“I won’t tell him how to be the mayor and he won’t tell me how to be the chief,” said McMillin, a former Jackson police officer.

Ben Allen, who resigned from the City Council in June because of health reasons, said the hiring of McMillin was a good move by Melton and that the sheriff likely will be confirmed by the city council.

It wasn’t immediately clear whether McMillin’s dual responsibility is specifically allowed under state law. Dale Danks, a former Jackson mayor who is Melton’s personal attorney, said there is “absolutely no prohibition.”

Melton was elected by a landslide in 2005 on promises to root out the crime problem that is blamed for suburban flight and an evaporating tax base. His crimefighting zeal led to the criminal charges in 2006.

Melton and his two bodyguards, Michael Recio and Marcus Wright, were accused of leading a group of teenagers with sledgehammers in smashing up the duplex. All were acquitted of the charges in April.

Melton said he and the sheriff were friends who have known each other for 25 years.

“It is our joint belief that by working together we can make a difference in this city, and the county and the state of Mississippi,” Melton said.

McMillin said he’s already met with some of the police officers who have been in a public feud with the mayor over his interference with their work. The situation reached a crescendo in October when Melton announced he would promote his bodyguards to powerful positions within the department.

Melton elevated Michael Recio to assistant chief apparently without discussing the promotion with Anderson. His other bodyguard, Marcus Wright, was named sergeant.

“If you get into a situation where the mayor, without any law enforcement training, tries to run the department over the chief’s head, then that creates a lot of confusion,” said Rich Roberts, spokesman for the International Union of Police based in Sarasota, Fla.

Roberts said the union has been in contact with local union leaders in Jackson, but he didn’t want to elaborate about the grievances.

“If an officer speaks out publicly, they put their job on the line,” Roberts said.