NEW ORLEANS (AP) — New Orleans police officers decided to “shoot first and ask questions later” when they gunned down two unarmed people and wounded four others on a bridge in Hurricane Katrina’s aftermath, a federal prosecutor said Monday during opening statements for a trial spotlighting one of the epic storm’s most notorious episodes.

The jury heard a vastly different account of the encounter on the Danziger Bridge from lawyers for five current or former officers charged in the deadly shootings. Defense attorneys said their clients feared for their lives and were justified in using deadly force.

“They stayed,” said Paul Fleming, a lawyer for former officer Robert Faulcon. “They didn’t desert. They didn’t go work other jobs. They stayed and did the best they could.”

Justice Department attorney Bobbi Bernstein said police plotted to plant a gun, fabricate witnesses and falsify reports to cover up “atrocities” and tried to use Katrina’s chaotic conditions as an excuse for gaps in their investigation.

“They lied because they knew they committed a crime,” Bernstein said. “They lied because they knew police officers were not allowed to shoot first and ask questions later.”

Faulcon, Sgts. Robert Gisevius and Kenneth Bowen and Officer Anthony Villavaso are charged in the shootings, which killed 17-year-old James Brissette and 40-year-old Ronald Madison, who was severely mentally disabled. Retired Sgts. Arthur Kaufman and Gerard Dugue are charged in the alleged cover-up, but Dugue will be tried separately from the other five who were indicted last year on federal civil rights charges.

Five other former officers already have pleaded guilty to participating in a cover-up to make the shootings appear justified. They are cooperating with the government and are expected to testify during the trial, which could last up to eight weeks.

The shootings broke out on the morning of Sept. 4, 2005, less than a week after the storm’s landfall. A group of police officers working out of a makeshift station piled into a Budget rental truck and drove to the bridge after hearing a radio call that other officers had taken fire.

Bernstein said Brissette was walking on the east side of the bridge with a friend, Jose Holmes, and several of Holmes’ relatives, when the officers pulled up in the truck and started firing at them, sending them scrambling for cover behind a concrete barrier. Holmes was lying wounded on the ground when Bowen walked up, pointed a gun at his stomach and fired a shot, according to the prosecutor.

“Jose clenched his stomach, and he reminded himself to breathe. And then Jose began to pray,” Bernstein said.

Holmes survived, but Brissette died on the east side of the bridge. On the west side, Faulcon allegedly shot Madison in the back with a shotgun as he and his brother, Lance Madison, were running away from the gunfire. Ronald Madison was lying on the ground when Bowen walked over and asked a fellow officer, “Is that one of them?” before he repeatedly stomped on the dying man, Bernstein said.

“Those words will tell you why he did what he did,” Bernstein said.

The officers have claimed they opened fire only after being shot at. They point to testimony less than a month after the shootings by Lance Madison, who said a group of teenagers started firing at him and his brother before they encountered police.

Fleming said the officers acted reasonably under dangerous circumstances, believing other officers already had been shot on the bridge before they arrived.

“Two officers dead or dying was what these officers had in their minds when they raced out there,” Fleming said.

Bernstein said the officers’ accounts of their actions, which they gave in taped interviews with police investigators, are contradicted by grainy footage shot by an NBC cameraman who was filming the incident.

“That tape is going to be an important piece of evidence for you,” she told jurors.

Police recovered no guns from the bridge that day, but Kaufman allegedly retrieved a gun from his garage and turned it in to the department’s evidence room six weeks after the shootings, trying to pass it off as a gun found at the scene. Bernstein described the cover-up as “ridiculously sloppy.”

“They were cavalier because they didn’t think they had to bother dotting any i’s or crossing any t’s,” she said.

Copyright 2011 The Associated Press.