NEW ORLEANS — A federal jury on Friday convicted five current or former police officers in deadly shootings on a New Orleans bridge after Hurricane Katrina, a high-profile victory for the Justice Department in its push to clean up the city’s troubled police department.

The case was a high-stakes test of the effort to rid the police department of corruption and brutality. A total of 20 current or former New Orleans police officers were charged last year in a series of federal probes. Most of the cases center on actions during the aftermath of the Aug. 29, 2005, storm, which plunged the flooded city into a state of lawlessness and desperation.

Sgts. Robert Gisevius and Kenneth Bowen, Officer Anthony Villavaso and former officer Robert Faulcon were convicted of civil rights violations in the shootings that killed two people and wounded four others on the Danziger Bridge less than a week after the storm. They face possible life prison sentences.

Retired Sgt. Arthur “Archie” Kaufman and the other four men also were convicted of engaging in a brazen cover-up that included a planted gun, fabricated witnesses and falsified reports. The five men were convicted of all 25 counts they faced.

Shaun Clarke, a defense attorney and former federal prosecutor who moved from New Orleans to Houston after Katrina, said the verdicts are “critically important” to the Justice Department’s reform efforts.

“It’s a huge verdict for the government,” he said. “Of all the cases concerning alleged misconduct by police officers after Katrina, this was the one that had the highest national profile.”

U.S. Attorney Jim Letten echoed that, saying the verdicts send a message that “public officials, and especially law enforcement officers, that they will be held accountable and that any abuse of power will have serious consequences.”

Faulcon was found guilty of fatally shooting Ronald Madison, a 40-year-old mentally disabled man, but the jury decided his killing didn’t amount to murder. Faulcon, Gisevius, Bowen and Villavaso were convicted in the death of 17-year-old James Brissette. Jurors didn’t have to decide whether Brissette was murdered because they didn’t hold any of the defendants individually responsible for causing his death.

Kaufman, who was assigned to investigate the deadly encounter on the bridge, wasn’t charged in the shootings.

New Orleans Mayor Mitch Landrieu, who invited the Justice Department last year to conduct a thorough review of the police department, said the verdicts “provide significant closure to a dark chapter in our city’s history.”

In March, the Justice Department issued a blistering report that said New Orleans police officers have often used deadly force without justification, repeatedly made unconstitutional arrests and engaged in racial profiling. Landrieu has said he expects the federal review to bring about court-ordered reforms.

Five former officers pleaded guilty to participating in cover-up of the bridge shootings and testified during the trial. Another former officer, retired Sgt. Gerard Dugue, has a separate trial scheduled to start in September.

Brissette’s mother, Sherrel Johnson, said she was relieved by the verdict after “a long, hard six years” and would now try to move on. But she lamented what her son has lost.

“For him there will be no prom, no baby, no nothing. My child will never have nothing,” she said.

Madison’s relatives said in a statement the family had waited six years to “find out what really happened on that bridge.”

Madison’s sister Jackie Madison Brown read the statement, which also said that after an event like Katrina, “all citizens, no matter what color or what class, deserve protection.”

After the verdict was read, Justice Department prosecutor Bobbi Bernstein became emotional, hugging the families of Madison and Brissette and holding hands with two of Madison’s sisters.

Defense attorney Roger Kitchens, who represented Villavaso, said he believed negative media coverage of the case tainted jurors.

“At this point, I don’t think it’s possible for a New Orleans police officer to get a fair trial in the city of New Orleans. And I don’t think they got one today,” he said.

Prosecutors said police had no justification for shooting unarmed, defenseless people trying to cross the bridge in search of food and help mere days after Katrina struck.

Defense attorneys argued, however, that police were shot at on the bridge before they returned fire.

Faulcon, the only defendant to testify, said he was “paralyzed with fear” when he shot and killed Madison, as he chased him and his brother, Lance Madison. Faulcon didn’t dispute that he shot an unarmed man in the back, but he testified that he had believed Ronald Madison was armed and posed a threat.

Prosecutors contended that Kaufman retrieved a gun from his home weeks after the shootings and turned it in as evidence, trying to pass it off as a gun belonging to Lance Madison. Police arrested Lance Madison on attempted murder charges, but a grand jury later cleared him.