A New Orleans police officer on trial for shooting unarmed civilians in the chaotic days after Hurricane Katrina told a jury on Wednesday that he acted out of fear he was about to be shot at.

Robert Faulcon is one of five officers on trial for a shooting that occured on New Orleans' Danziger bridge nearly a week after Hurricane Katrina, when much of the city was under water and civil order had largely broken down. The shooting wounded four and killed two, including a 40-year-old mentally disabled man, and crystallized a sense of outrage that poor and minority residents were victimized and abandoned as floodwaters engulfed the city.

Faulcon admitted to shooting down the disabled man, Ronald Madison, despite the fact that Madison had not fired at him. He recounted feeling "indescribable fear" after seeing civilians with guns. Another one of the police officers on trial testified having fired warning shots into the air, something that may have prompted Faulcon to act.

"I became paralyzed with fear, really, that we were going to be shot at," he said. "I knew we were going into a bad situation," he added. "I just expected to be shot at."

Faulcon also repeatedly invoked the aftermath of Katrina to try and depict a ravaged city where confusion reigned. He said his wife, who was nine months pregnant, evacuated the city the day before the hurricane and that he did not learn that she had given birth to his son until nearly three weeks later.

The officers on trial face allegations that they attempted to make the people fired upon appear guilty by planting a gun at the crime scene, among other actions. A previous investigation has already produced guilty pleas from five other police officers who admitted to trying to cover up what transpired, including authoring a report claiming that the civilians had opened fire on officers.