A fifth police officer got six years for his role in trying to cover up the shootings, The (New Orleans) Times-Picayune reported.
U.S. District Judge Kurt Englehardt heard statements in the morning from relatives of the men shot on the Danziger Bridge.
Lance Madison, who was arrested there, described seeing his mentally challenged brother, Ronald, 40, "gunned down and killed without mercy."
"You are the reason I can no longer trust law enforcement," Madison said.
Sherrel Johnson, whose son, James Brissette, 17, was also killed, said she cannot understand what the officers were thinking.
"He didn't deserve this," she said. "He never even knew what hit him."
The shootings occurred six days after Katrina on a bridge over the Industrial Canal. Investigators said officers who arrived in a rental truck sprayed an unarmed group with automatic weapon fire, killing Brissette and wounding several others and then fabricated a story that they had been under fire. One officer, Robert Faulcon Jr., 48, shot Ronald Madison in the back.
Faulcon was sentenced to 65 years. Kenneth Bowen, 38, and Robert Gisevius Jr., 39, who were both sergeants at the time of the shootings, got 40 years, and Anthony Villavaso II, 35, got 38 years.
Arthur "Archie" Kaufman, 55, who retired as a sergeant in 2011, got six years for the coverup. He was ordered to surrender in late May to begin his sentence, while the others are already behind bars.