A Michigan cop has been placed on administrative leave so city officials can investigate why he decorated his home with Confederate flags and a framed membership application for the Ku Klux Klan.

The cop was last in the news a decade ago for shooting and killing a black man, for which he was cleared of any wrongdoing.

Muskegon City Manager Frank Peterson was alerted to Officer Charles Anderson’s disturbing memorabilia after an African-American man toured the white officer’s home, which is for sale, according to the statewide news site MLive. Rob Mathis wrote on Facebook that the five-bedroom home was littered with Confederate memorabilia. The KKK application was hanging in one of the bedrooms. It lacks a name and signature.

“I feel sick to my stomach knowing that I walk to the home of one of the most racist people in Muskegon hiding behind his uniform and possibly harassing people of color and different nationalities,” Mathis wrote Wednesday in his now-viral Facebook post.

The post didn’t name Anderson, but Peterson confirmed to MLive that the home Mathis toured was the officer’s.

”The City of Muskegon requests your patience as we thoroughly investigate this issue,” the city said in a statement on its Facebook page Thursday. “Further information will be available upon completion of the investigation.”

Anderson, who's been with the force for more than two decades, fatally shot a black man in 2009, according to MLive. The 48-year-old officer killed 23-year-old Julius Johnson after the man fled on foot after a traffic stop and then allegedly beat the officer in the head. Anderson had been called in as back-up apparently relating to the smell of marijuana, and said he shot Johnson because he feared for his life. The local prosecutor said Anderson was justified in using deadly force.

Anderson told MLive that he’s unable to make a statement. His wife, Rachael Anderson, told local NBC affiliate WOOD that he’s not a Klan member.

“He can’t say anything right now. I wish we could because it would probably set a lot of things straight,” she said.

The discovery of the cop’s Confederate memorabilia comes at a tense time for police across the nation. A Reveal investigation published in June showed hundreds of cops were engaged in hateful, sexist, racist Facebook groups, spurring 50 police departments to investigate their ranks for bad behavior. The Philadelphia Police Department suspended 13 police officers last month for racist and discriminatory Facebook posts.

Michigan, meanwhile, has a long history with the Ku Klux Klan and other white supremacist organizations. Muskegon was home to the locally infamous “Blue Lake Bomber,” a Klan leader who killed three people with a mail bomb in 1926. At the time, the Klan was attempting to make a state headquarters in nearby Grand Rapids.