Henry Glover, the man who was shot by former New Orleans police officer David Warren just days after Hurricane Katrina, was simply lighting a cigarette when he was killed, a relative of the victim testified Wednesday.

Bernard Calloway said he and 31-year-old Glover intended to pick family members up from Glover's New Orleans apartment and head out of town four days after the devastating 2005 storm. Glover, driving a stolen truck, stopped at a curb behind a strip mall where a sister-in-law of his said she had left a suitcase. Warren was nearby, on patrol on the second-floor area outside a police substation located in the mall.

Testifying on the first day of Warren's retrial, Calloway said Glover was standing next to the truck and lighting a cigarette. Calloway said that as he turned back to the suitcase, he heard gunfire.

"I heard POW! – A gunshot. I heard a voice that said, 'Leave now,'" Calloway said. The men fled in opposite directions. Calloway looked back and saw Glover stumble. He looked back again and saw the victim fall. Calloway then ran back to help Glover, who was bleeding.

"He just said to tell his mama that he loved her. He was holding his chest," Calloway testified.

The trial is the second in three years for Warren, who was serving a prison sentence of nearly 26 years when a federal appeals court in December overturned a manslaughter conviction handed down in 2010.

The 5th US Circuit Court of Appeals ruled Warren should have been tried separately from four other officers charged with participating in a cover-up. Ex-officer Gregory McRae was sentenced to more than 17 years in prison for burning Glover's body after he was gunned down. Another former officer, Travis McCabe, was convicted of writing a false report on the shooting. Two other former officers were acquitted.

Warren, who is charged with violating Glover's civil rights and with using a weapon in a violent crime, does not dispute having fired the bullet that killed Glover on September 2, 2005, using his personal SIG Arms Model SG 550-SP rifle. What jurors must decide is whether the shooting was justified.

During opening arguments, Assistant US Attorney Jared Fishman told the jury Warren believed looters were animals who deserved to be shot. The defendant used his personal rifle and high-powered scope to shoot a man who was running away with a locked gate and about 60 feet between them – relatively close range for a gun that is accurate over hundreds of yards.

"Even though Henry Glover posed no threat ... David Warren reached for his personal assault weapon," Fishman said. "He looked through the magnification red-dot scope and pulled the trigger."

Defense attorney Julian Murray described Warren as an honorable man who knew firsthand that a looter in the same general area had shot another officer in the head, believed that Glover had a weapon, believed that his own life was in danger, and shot a man walking toward an unlocked gate.

"He reacted because he thought he was going to be killed. In the totality of the circumstances ... it was a reasonable expectation," Murray said.

While jurors were out of the courtroom, US District Judge Lance Africk noted that the jury did not include anyone who knew that Glover's body had been burned, that there had been a cover-up or that this is Warren's second trial.

Warren was among 20 officers charged in a series of federal investigations of alleged police misconduct in New Orleans. In 2011, the Justice Department issued a scathing report alleging a pattern of discriminatory and unconstitutional conduct by police. The city and the Justice Department reached an agreement calling for sweeping changes in police policy, though the city has since objected to the potentially expensive agreement.