A rookie officer faces trial on Thursday for the shooting death of 28 year old Akai Gurley, the unarmed Black man that was shot in the staircase of his East New York, Brooklyn building by the NYPD officer in November 2014.

Peter Liang, who is also now 28, may have to testify as to why he had his service weapon out of his holster ,which was fired from a higher floor and struck Gurley in the chest, killing him. Liang had been on the job for less than two years when he and his partner Shaun Landau were doing a vertical check inside of the building of Gurley’s residence in the Louis H. Pink Houses in the East New York section of Brooklyn.

Liang had his weapon out and finger on the trigger when he was allegedly startled by Gurley and firing the fatal shot into his chest, according to prosecutors. According to Liang’s lawyers, the shooting was accidental because of a defective trigger.

Jury selections are slated for Thursday while opening arguments are scheduled for Monday.