An NYPD officer testified Tuesday that it’s common for officers — like a rookie cop accused in the fatal housing project shooting of an unarmed man — to have guns drawn while patrolling project stairwells.

Prosecutors called Officer Andrae Fernandez, an eight-year veteran, to testify at the Brooklyn trial of NYPD Police Officer Peter Liang, who is charged with manslaughter in the death of 28-year-old Akai Gurley.

Liang’s 9-mm handgun accidentally discharged in a darkened stairwell of the Louis H. Pink Houses in East New York on the night of Nov. 20, 2014.

StoryADA: NYPD rookie uncaring after fatal shooting

A bullet struck Gurley in the chest. According to testimony, several attempts to revive Gurley using CPR failed. He was pronounced dead later at a hospital.

Liang and his rookie partner were conducting patrols inside the housing development on the eighth-floor stairwell, according to testimony and police. Holding his gun and flashlight, Liang opened a stairwell door and his gun discharged, a bullet striking Gurley as he and his girlfriend were on the seventh-floor landing, according to testimony and an NYPD account of the shooting.

The rookie officer with less than 18 months on the job the night of the shooting is expected to take the stand next week. He faces charges of second-degree assault, criminally negligent homicide, reckless endangerment and official misconduct. Liang has pleaded not guilty. If convicted, he faces a maximum sentence of 5 to 15 years in prison.

advertisement | advertise on newsday

Liang’s attorney, Robert Brown, asked Fernandez under cross-examination if it was “fair to say when doing vertical patrols you were trained to have your gun out and have your finger by the trigger?”

“Yes,” replied Fernandez, who arrived at the scene shortly after the fatal shooting. Fernandez also testified that he had to push open the eighth-floor stairwell door that Liang had to open earlier.

Akai Gurley is seen in this Facebook photo. Photo Credit: Facebook

“I first turned the knob and it didn’t work. When I tried to push it open it didn’t move,” Fernandez said. “I gave my right shoulder and the door opened.”

Get the Newsday Now newsletter!

The best of Newsday every day in your inbox.

Fernandez also testified that he administered CPR to Gurley.

“I yelled at him to stay with me. Mr. Gurley was unresponsive,” Fernandez told Brown.

State prosecutors also submitted a haunting video of the darkened stairwell where Gurley was shot. It was illuminated with a flashlight taken by police investigators. Det. Matthew Steiner of the NYPD Crime Scene Unit testified that the bloody clothing and baseball cap near a pool of blood belonged to Gurley.