NEW ORLEANS, Louisiana — Five police officers on trial in the shooting deaths of civilians in the chaotic aftermath of Hurricane Katrina were portrayed Tuesday in closing arguments as criminals or heroes.

“It was unreasonable for these officers to fire even one shot,” said Assistant US Attorney Theodore Carter, who reminded jurors of video footage that showed they unleashed “54 seconds of gunfire.”

The trial, which began five weeks ago, focuses on an incident on September 4, 2005, as two families whose homes were devastated by Katrina’s flood waters were crossing New Orleans’s Danziger Bridge.

In what prosecutors have described as a “hail of gunfire,” two people were killed, both African Americans, and four were wounded.

Ronald Madison, a 40-year-old mentally challenged man described by family members as gentle and loving, was shot several times in the back and died at the scene.

James Brissette, a high school student who friends said was nerdy and studious, also died on the bridge.

The case has put on display two radically different narratives not just of the incident on the bridge, but of the overall actions of police in the days after Hurricane Katrina wreaked havoc on the city.

The prosecution has said that officers felt that the law did not apply to them and began covering their tracks immediately after the incident, when they discovered they had killed unarmed civilians.

The elaborate cover-up allegedly involved the collusion of top officers, secret meetings, invented witnesses and manufactured evidence.

Arguing that the officers stuck together to shape their stories, Carter said: “in another situation, that’s admirable. But here it’s criminal.”

The defense has insisted the officers are heroes who rescued people and “fought bad guys” in a chaotic and lawless city at a time when many of their fellow police had evacuated.

“These are the life and death decisions we call upon officers to make every day,” declared Paul Fleming, one the defense attorneys.

Fleming, who represents former officer Robert Faulcon, accused the government of overreaching in their pursuit of these officers, abusing the grand jury process and threatening witnesses with “a pattern of harassment and intimidation heaped upon anyone who said something they didn’t like.”

In a heated appeal, fellow defense attorney Frank Desalvo called the prosecution’s case “meaningless, emotional drivel” and criticized the Justice Department for going after the law enforcement officers.

“We know that the United States is the greatest country on earth and the only thing wrong with it is the people running the government,” Desalvo said.

The officers involved in the shooting — Kenneth Bowen, Robert Gisevius, Anthony Villavaso and Faulcon — could receive life sentences if convicted of federal civil rights violations.

They are also charged with obstructing justice during the subsequent investigations by falsifying reports, inventing witnesses and planting evidence.

Five officers who aided in the conspiracy have already pleaded guilty and agreed to testify against their fellow officers in exchange for lighter sentences.

Sergeant Arthur Kaufman, who was not present at the shooting, is charged only in the conspiracy and could receive a maximum penalty of 120 years behind bars.

Sergeant Gerard Dugue, another officer who is accused of aiding in the conspiracy, will be tried separately in September, and faces a maximum penalty of 70 years.

Focus now turns to the jury, which will begin deliberating Wednesday on the 25 charges faced by the officers, after receiving final jury instructions from US District Judge Kurt Engelhardt.