NEW ORLEANS -- A federal jury on Friday convicted five current or former New Orleans police officers of civil rights violations in one of the lowest moments for city police in the chaotic aftermath of Hurricane Katrina: the shooting deaths of a teenager and a mentally disabled man as they crossed a bridge in search of food and help.

Three officers and one former officer 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. All four and a retired police sergeant 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.

The case was a high-stakes test of the Justice Department's 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.

Convicted were New Orleans police Sgts. Robert Gisevius and Kenneth Bowen, Officer Anthony Villavaso and former officer Robert Faulcon. They face possible life prison sentences.

Jurors found Faulcon guilty in the fatal shooting of 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.

Retired Sgt. Arthur "Archie" Kaufman and the other four defendants also were convicted of engaging in a cover-up.

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."

Five former officers pleaded guilty to participating in a 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.