After a federal trial that lasted five weeks, five current or former New Orleans police officers were convicted Friday in a series of deadly shootings on a bridge in the aftermath of Hurricane Katrina.

Prosecutors contended that the officers shot unarmed citizens without justification and without warning on Sept. 4, 2005 on a New Orleans bridge following the destruction wrought by Katrina. Two people were killed and four others were wounded in the shootings.

During the trial, prosecutors said the officers tried to cover up the shootings after they occurred, with made-up witnesses, falsified reports and a planted gun in the attempt to show that the shootings were provoked.

All five officers were convicted on charges related to the cover-up. Four of the officers were charged with civil rights violations and convicted on all counts. The federal jury did not find, however, that two people who died in the shootings were killed with murderous intent.

Convicted Friday in federal court were former officer Robert Faulcon, Sgts. Robert Gisevius and Kenneth Bowen, officer Anthony Villavaso and retired Sgt. Arthur Kaufman.

The police officers turned themselves in to authorities in 2007 after the U.S. Justice Department began an effort to clean up New Orleans' police department, long known for its corruption and civil rights violations. Citizens complained loudly in events during the aftermath of Hurricane Katrina that police treated them unfairly, even brutally.

Defense attorneys in the case argued that the police officers were returning fire and reasonably believed their lives were in danger when the shots were fired, killing two people. They said the officers had rushed to respond to a distress call from a fellow officer and were greeted hostily.

Assistant U.S. Attorney Theodore Carter aruged for the prosecution in closing comments, however, that the police officers had no justification in shooting unarmed citizens. He argued the victims were defenseless citizens merely trying to cross the bridge in search of food in the days after Hurricane Katrina flood New Orleans, displacing tens of thousands of residents.

"It was unreasonable for these officers to fire even one shot, let alone dozens," Carter argued, according to the Associated Press.