MUSKEGON, Mich. (WOOD) — The man who blew the whistle on a Muskegon city police officer who had items associated with white supremacy in his house is now facing threats.

Rob Mathis told News 8 that police came to him Monday to inform him that someone made a credible threat against him on social media.

The photo of a KKK application in Charles Anderson’s home that Rob Mathis posted on social media. (Courtesy)

Mathis was looking to buy a home recently when he toured a house owned by Muskegon officer Charles Anderson and noticed Confederate flags and then a framed Ku Klux Klan application in the bedroom. Mathis posted about it on social media and when city officials caught wind of it, they placed Anderson on leave and launched an internal investigation.

When News 8 went to the Anderson home after he was put on leave, he did not come to the door and his wife refused to comment in detail. She did say her husband is not a KKK member.

Anderson has been a police officer for more than 22 years.

An undated photo of Charles Anderson.

In 2009, he shot and killed Julius Johnson, a black man, who had attacked him during a foot chase in the line of duty. Anderson was cleared of wrongdoing and the county prosecutor says there’s no reason to review that decision, but at the time, the NAACP said it wanted a federal inquiry into the death.