Opening statements began Wednesday in the retrial of a former New Orleans policeman who shot and killed a man four days after Hurricane Katrina.

David Warren is charged with violating 31-year-old Henry Glover's civil rights and using a weapon in a violent crime.

Warren was guarding a police substation from a second-floor balcony when he shot Glover in 2005. He previously testified that he thought Glover had a gun. He was convicted of manslaughter in 2010, but a federal appeals court overturned the conviction.

The court ruled he should have been tried separately from officers charged in a cover-up designed to make Glover's shooting appear justified.

In opening statements Wednesday, jurors heard two very different accounts of Glover's death four days after Hurricane Katrina plunged the city into chaos.

Assistant U.S. Attorney Jared Fishman argued that Warren believed looters were "animals who deserved to be shot" — and that he used his personal rifle equipped with a high-powered scope to shoot a man who was running away from him.

Defense attorney Julian Murray countered that Warren was an honorable man who believed Glover had a weapon and believed his own life was in danger.

Warren was serving a prison sentence of nearly 26 years when the appeals court overturned a 2010 manslaughter conviction.

During jury selection for the retrial, Africk emphasized that Warren's case is unrelated to other federal cases, including those alleging police misconduct. He specifically mentioned deadly police shootings on New Orleans' Danziger bridge after Hurricane Katrina.

Warren's attorneys argued in October that some prospective jurors mistakenly believed he was involved in that case.

Warren was among 20 officers charged in a series of federal investigations of alleged police misconduct in New Orleans. Five pleaded guilty; three were acquitted; four convictions were upheld; seven await retrials after their convictions were overturned; and another trial ended in a mistrial because of a prosecutor's remarks.

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.