A jury in Brooklyn found Peter Liang guilty in connection with the death of Akai Gurley, 28, who was killed by a bullet fired from Liang's gun on Nov. 20, 2014, that ricocheted off a wall.
Liang, a rookie cop at the time, was on patrol inside a Brooklyn public housing project with his partner and drew his gun upon entering a pitch-black stairwell.
He fired a single bullet that caromed off a wall and into the chest of Gurley, who was walking one floor below.
At trial, Liang, 28, testified that a sudden noise startled him, causing his finger to slip onto the trigger and fire the gun.
But prosecutors argued that Liang fired toward the sound and that he must have known only another person could have caused the noise that surprised him.
Liang and his partner, Shaun Landau, debated whether to call in the shot, with Liang expressing concern that he might be fired.
It was only after descending the stairs, Liang said, that he realized the errant bullet had hit Gurley.
"Oh my god, someone's hit," a tearful Liang recalled saying upon finding a bleeding Gurley lying on a landing, as his girlfriend frantically tried to revive him.
The shooting added to nationwide protests over the use of police force against minorities, though Liang, a Chinese-American, was not accused of deliberately killing Gurley.