NEW ORLEANS — A federal appeals court ordered a new trial Monday for a former New Orleans police officer convicted of manslaughter in the fatal shooting of a man whose burned body turned up after Hurricane Katrina.

A three-judge panel of the 5th U.S. Circuit Court of Appeals threw out David Warren’s 2010 convictions, saying a judge should have separated his trial from four other officers charged in the 2005 death of 31-year-old Henry Glover.

Unlike the other officers, two of whom were acquitted at trial, Warren wasn’t charged with participating in a cover-up of Glover’s death. The 5th Circuit judges agreed with Warren’s argument that the “spillover effect” from other evidence unrelated to the shooting, including the burning of Glover’s body, prevented him from getting a fair trial.

“Some of the evidence and testimony would have been inadmissible against Warren had he been tried alone, and we are convinced that the severely emotional nature of the testimony and photographs (of Glover’s remains) prejudiced Warren,” Judge E. Grady Jolly wrote.

Edna Glover, Henry’s mother, said she can’t bear the thought of enduring another trial.

“I just wish it would come to a close,” she said.

Rebecca Glover, Henry’s aunt, said she was devastated by the ruling.

“We thought we could pick up our pieces and go on, but we’ve got to rehear this all over again?” she asked. “It hurts. It really hurts.”

The panel also reversed one of the convictions of former Officer Gregory McRae, who burned Glover’s body in a car after a good Samaritan drove the dying man to a police compound at a school. The judges upheld McRae’s other civil rights convictions but ordered him to be resentenced.

U.S. District Judge Lance Africk sentenced Warren to more than 25 years in prison for shooting Glover outside a strip mall. Africk sentenced McRae to more than 17 years in prison.

The 5th Circuit also upheld Africk’s decision to order a new trial for a third former officer, Travis McCabe, who was convicted of writing a false report on the shooting. Africk said he believes jurors probably would have acquitted McCabe if they had seen evidence that surfaced after the trial — a different copy of the report that McCabe is accused of doctoring.

Jurors acquitted two other former officers who were charged with participating in a cover-up of Glover’s killing.

The convictions in the Glover case were a milestone in a sweeping Justice Department probe of police misconduct that resulted in charges against 20 current or former New Orleans officers.

Convictions in another high-profile case also could be in jeopardy.

Five former officers convicted in the shootings of unarmed residents on a New Orleans bridge in Katrina’s aftermath have asked a judge to order a new trial, claiming prosecutors engaged in a “secret public relations campaign” against them. In a filing last month, a judge said their request is “still a longshot in terms of relief” but isn’t frivolous and merits further inquiry.

Warren was a rookie patrol officer when Katrina struck. He was guarding a police substation at the mall less than a week after the storm’s landfall when Glover and a friend pulled up in a truck.

Warren testified that Glover and the friend ran toward a gate that would have given them access to the building and ignored commands to stop. Warren said he thought Glover had a gun and posed a threat when he shot him with an assault rifle from a second-floor balcony. Prosecutors said Glover wasn’t armed and accused Warren of shooting him in the back.

Warren’s attorneys had urged Africk before, during and at the conclusion of the trial to sever his case from the other defendants.

“There’s no way the jury can compartmentalize all that stuff,” said Rick Simmons, one of Warren’s lawyers. “The spillover effect was devastating to our defense.”

The 5th Circuit didn’t fault Africk for declining to sever Warren’s case before trial. But the panel said the judge abused his discretion when he denied that request at the conclusion of the testimony, which became “increasingly inflammatory” and irrelevant to Warren’s case as the trial wore on.

Jolly’s decision says the record “strongly suggests that the government was attempting to try the cases against each defendant as a whole piece, in effect a conspiracy, involving each of the defendants in a grand scheme ... to engage in criminal conduct to protect Warren for his role in Glover’s shooting.”

Simmons said he hadn’t spoken to Warren about the ruling yet but that Warren’s wife was ecstatic.

“She’s been hoping this would happen,” he said. “This will be their third Christmas away from each other.”

Spokeswoman Dena Iverson said the Justice Department was reviewing the decision. Simmons said he expects prosecutors to ask the full 5th Circuit to rehear the case.

The 5th Circuit said there wasn’t sufficient evidence to support McRae’s conviction on a charge he denied Glover’s relatives the “right of access to courts.” Prosecutors claimed that burning Glover’s body frustrated a lawsuit that his relatives could have pursued.