New York City cop tearfully describes accidental shooting of unarmed black man
New York City Police (NYPD) officer Peter Liang (C) departs the criminal court after an arraignment hearing in the Brooklyn borough of New York City February 11, 2015. REUTERS/Brendan MCDermid

A New York City police officer charged with fatally shooting an unarmed black man in an unlit Brooklyn stairwell took the stand at his manslaughter trial on Monday, tearfully describing what he portrayed as a tragic accident.

Peter Liang was entering a pitch-black stairwell inside a public housing project with his gun drawn on Nov. 20, 2014, when he said a noise startled him, causing his body to tense and his finger to pull the trigger of his service weapon.

He and his partner argued briefly over whether to report the shot, with Liang saying he was going to be dismissed from the force. Moments later, Liang headed downstairs and realized the bullet had ricocheted off a wall and into the chest of 28-year-old Akai Gurley, one floor below.

"His eyes were rolled back," Liang said, his voice breaking. "He was just laying there very still."

Prosecutors have accused Liang of misconduct and criminal negligence for failing to report the shot immediately and for having drawn his weapon in the first place. They have also said he did not offer Gurley medical aid despite having CPR training.

But Liang, now 28, said he understood that officers have the discretion to unholster their guns if they are worried about their safety.

The shooting added to tensions across the United States over the use of force against minorities by police officers, though Liang, who is Chinese-American, has not been accused of deliberately firing at Gurley.

The defense has emphasized the dangers inherent in patrolling crime-ridden public housing buildings. That argument was underscored last Thursday night, when two officers were shot during a similar patrol inside the stairwell of a Bronx public housing complex.

Jurors will weigh Liang's account with versions offered by Melissa Butler, Gurley's girlfriend, who described frantically trying to administer aid while Liang stood by, and Liang's partner Shaun Landau, who testified under an immunity deal.

Liang, who was a rookie officer, said he felt it was more important to summon help on the radio than to try to assist Gurley himself.

"I was panicking," he said. "I was in shock and disbelief that someone was actually hit."

Liang was forced to leave the courtroom to compose himself during his direct testimony, which lasted about half an hour. As cross-examination began, Assistant District Attorney Joseph Alexis pointed out that Liang had received extensive firearms training.

The trial is expected to end early this week.

(Reporting by Joseph Ax; Editing by Scott Malone and Dan Grebler)