(CNN) -- Five current or former police officers were found guilty Friday on a combined 25 counts of civil rights violations tied to fatal shootings on New Orleans' Danziger Bridge in the chaotic aftermath of Hurricane Katrina, Justice Department officials said.

Jurors reached a verdict in the closely watched trial after three days of deliberations.

The shootings occurred on Danziger Bridge on September 4, 2005, six days after much of New Orleans went underwater after the powerful hurricane slammed into the Gulf Coast.

Prosecutors contend the officers opened fire on an unarmed family, killing 17-year-old James Brissette and wounding four others. Minutes later, one of the officers shot and killed Ronald Madison, a 40-year-old man described by Justice officials as having severe mental disabilities.

Madison was trying to flee the scene when he was shot, according to a Justice Department statement. One of the officers allegedly "stomped and kicked" Madison before he died, the statement noted.

Officers Kenneth Bowen, Robert Gisevius, Robert Faulcon and Anthony Villavaso were convicted in the shootings along with a fifth defendant, former detective Arthur Kaufman.

The five men are scheduled to be sentenced on December 14. Bowen, Gisevius, Faulcon and Villavaso are facing potential multiple life sentences, as well as additional penalties for charges tied to a conspiracy to cover up what happened on the bridge. Kaufman faces a maximum penalty of 120 years in prison.

"Today's verdict by these jurors sends a powerful, a powerful, unmistakable message to public servants, to law enforcement officers and to the citizens we serve and indeed to the world," U.S. Attorney Jim Letten said. "That message is that public officials and especially law enforcement officers will be held accountable for their acts, and that any abuse of power, especially that power that violates the rights and the civil liberties of our citizens, will have serious consequences."

"The citizens of this country will not, should not, and we intend that they will never have to fear the individuals who are called upon to protect them," Letten declared.

U.S. Attorney General Eric Holder said he hopes the verdict will eventually help generate greater trust between residents of New Orleans and the city's scandal-plagued police department.

"The officers convicted today abused their power and violated the public's trust during the aftermath of Hurricane Katrina -- exacerbating one of the most devastating times for the people of New Orleans," Holder said in a written statement.

"I am hopeful today's verdict brings justice for the victims and their family members, helps to heal the community and contributes to the restoration of public trust in the New Orleans Police Department."

New Orleans Mayor Mitch Landrieu said the verdicts "provide significant closure to a dark chapter in (the) city's history."

During closing arguments Tuesday, the defense had asked the jury to consider the stressful circumstances the officers were operating under following Katrina.

The shootings took place during a week of dire flooding, rampant looting and death by drowning. Police were strained, beset by suicides and desertion.

Local prosecutors filed similar charges, but no one was convicted. Federal prosecutors then moved in and launched an investigation.

Other officers have already been convicted in connection with the shootings. They include Michael Hunter, who pleaded guilty last year to conspiracy to obstruct justice. Hunter was sentenced to eight years in prison.

According to court documents, Hunter drove in a rental truck to Danziger Bridge with other officers to respond to a radio call about gunshots and reports that officers on the nearby Interstate 10 bridge had come under fire.

At the time, New Orleans police said they got into a running gun battle with several people.

That's when officers encountered the Madison brothers, Ronald and Lance.

Lance Madison told CNN he and his brother had left their flooded home and were crossing the bridge to find shelter. They were unwittingly headed to an area where armed looters were marauding, he said.

He said police officers were the only ones shooting as he and his brother ran for safety. A witness told CNN in 2006 that police shot Ronald Madison in the back as he ran toward a motel at the bottom of the bridge.

"Hunter ... admitted that he was present on the west side of the Danziger Bridge when an officer, identified as Officer A, shot and killed Ronald Madison, a civilian who was running away from officers with his hands in view, and did not have a weapon or pose a threat," the Justice Department said.

Hunter admitted that officers on the east side of the Danziger Bridge fired at civilians, even though the same civilians did not appear to have any weapons, the Justice Department said.

CNN's Michael Pearson, Terry Frieden, and Alan Silverleib contributed to this report