A judge appointed a special prosecutor Wednesday to investigate a white police officer’s fatal shooting of a black man in the Indiana city where Democratic presidential candidate Pete Buttigieg is mayor.

A St. Joseph County judge named Richard Hertel from southeastern Indiana’s Ripley County as the special prosecutor to oversee the investigation into Eric Logan’s shooting . County Prosecutor Ken Cotter said he sought a special prosecutor to “avoid any appearance of impropriety, conflict of interest or influence upon the ultimate prosecutorial decision to be made,” the South Bend Tribune reported .

The fatal June 16 shooting of the 54-year-old Logan by South Bend Sgt. Ryan O’Neill prompted Buttigieg, who’s seeking the Democratic presidential nomination, to leave the campaign trail for several days to answer questions about public safety and race. Buttigieg had said he wanted an independent investigator appointed in the case.

Buttigieg’s campaign did not immediately respond Wednesday to a request by The Associated Press for comment on Hertel’s appointment.

Police have said that Logan was armed with a knife when he approached O’Neill and that O’Neill shot him. Prosecutors have said Logan’s shooting was not recorded by the officer’s body camera.

In a statement tweeted Wednesday by South Bend’s police union, O’Neill said he and his family never expected “being thrown into the middle of a Presidential campaign.” O’Neill, who remains on paid administrative leave following the shooting, also said he and his family face “intense pressure.”

Logan was shot after O’Neill responded to a call about a suspicious person going through vehicles, a prosecutor investigating the case has said. O’Neill spotted Logan leaning inside a car. When confronted, Logan approached O’Neill with a 6- to 8-inch knife raised over his head, the prosecutor said. O’Neill fired twice, with the other shot hitting a car door.

Buttigieg said Monday that he had written the U.S. Department of Justice in response to Logan’s fatal police shooting.

The Indianapolis Star obtained a copy of Buttigieg’s letter to the federal agency, in which he writes that Logan’s shooting has “touched off a painful discussion” in his northern Indiana city. Buttigieg also wrote that he considers it “imperative that there be absolutely no racism in our city’s Police Department.”

Buttigieg’s letter stops short of requesting a federal investigation, but says he would “welcome the opportunity to learn more about the ways the U.S. Department of Justice could assist our community,” The Star reported .

Logan’s family is suing O’Neill in federal court, accusing him of using excessive deadly force. The lawsuit also names the city of South Bend as a defendant but does not name Buttigieg.

(AP)