SOUTH BEND, Ind. — Mayor Pete Buttigieg took a third day off from the campaign trail Wednesday to confront a crisis over the fatal police shooting of a black resident of South Bend, Indiana. Buttigieg said he was “extremely frustrated” that the white officer’s body camera was switched off at the time.

The shooting of the 54-year-old man revived long-standing mistrust by some black residents of the city police and of Buttigieg, and it has presented the mayor, a Democratic presidential candidate, with a national leadership test just a week before the first primary debates.

The case has revived scrutiny of Buttigieg’s history of sometimes strained relations with African-Americans in South Bend. The issue is echoing in the Democratic primary as Buttigieg, 37, seeks to improve his support with black voters.

After addressing a half-dozen newly sworn-in officers — all white — Wednesday morning, Buttigieg, the son of two Notre Dame professors, acknowledged to reporters outside police headquarters that he had only a “theoretical” understanding of the charged issue of race and policing when he took office nearly eight years ago.

“I’ve learned about how raw these issues are,” he said. “I’ve learned that this is a mix of not only distant historical issues, but of things happening around us every day.”

In his speech to the new recruits, Buttigieg stressed that everyone in uniform is “burdened” with the history of racial injustice between police and minority communities, which has lately been heightened by what Buttigieg called “a seemingly constant series of stories and videos from around the country showing abuses that tarnish the badge and fuel mistrust.’’

Buttigieg was scheduled to meet with community leaders at South Bend’s Civil Rights Heritage Center late Wednesday afternoon.

For many black voters in South Bend, issues of personal safety and policing are the most visceral way they perceive elected officials.

“How many people judge a mayor in the African-American community is how you handle your police department,” Oliver Davis, a black member of the South Bend City Council who has criticized Buttigieg, said Tuesday.

Davis said minority groups’ trust in South Bend police officers — only 10% of whom are black or Hispanic — was low. That mistrust has inflamed suspicions about the events that led to the shooting early Sunday morning of Eric Logan by a white officer.

Court records show that the officer, Sgt. Ryan O’Neill, has previously been accused of using racially charged language and excessive force against black suspects.

O’Neill, a 19-year veteran of the department, was twice sued in 2008 by black residents he had arrested, court records show. Both suits, filed in federal court on forms provided to the jailed suspects, were dismissed when the men did not pay filing fees to continue.

A former South Bend police officer, David Newton, complained to superiors in 2008 that O’Neill had made derogatory remarks about interracial relationships and “black meat” to another officer. A spokesman for the South Bend Police Department, Ken Garcia, said Tuesday that an internal investigation found that Newton’s assertion was “not sustained.”

The police union did not respond to requests for comment from O’Neill.

According to officials, O’Neill shot and killed Logan while responding to a report of someone breaking into cars downtown. O’Neill responded without using his lights and sirens, which would automatically have triggered his body camera. Nor did O’Neill turn on the camera manually when he exited the police car. O’Neill shot Logan once in the abdomen after he refused to drop a knife when O’Neill ordered him to do so, officials said.

Late Tuesday, Buttigieg issued an order that all officers must activate their body cameras in all working interactions with civilians. He said the reasons O’Neill’s was not on would be examined in an internal affairs review, which would follow an investigation by the county prosecutor of whether charges are warranted against O’Neill.

South Bend purchased body cameras under Buttigieg and implemented bias training for officers, among other measures designed to increase community trust of the police.

The efforts stem from Buttigieg’s firing of the city’s first black police chief in 2012, which Buttigieg acknowledged created a yearslong rift with African-Americans in South Bend.

“For seven years there has been a concern there is a, quote, cancer within our Police Department,” said Davis, who has led the City Council’s effort to gain access to tapes that allegedly document South Bend police officers making racist comments. “The issue of trust is huge here.”

This article originally appeared in The New York Times.