NEW YORK (CBSNewYork/AP) — An NYPD police lieutenant said Thursday in the manslaughter trial of Akai Gurley that rookie officer Peter Liang was “shaken” after the fatal shooting.

Liang shot Gurley on Nov. 20, 2014 while he and his partner were patrolling the Pink Houses on Linden Boulevard in East New York amid reports of a spike in violent crime.

NYPD Lt. Vitaliy Zelikov said on the stand that Liang told him that he shot Gurley by accident.

Zelikov told the courtroom Liang “appeared frozen” and was “staring off into space” after the shooting, WCBS 880’s Irene Cornell reported. The lieutenant described Liang as shaken, distressed and hyperventilating after shooting Gurley.

Defense attorney Robert Brown told the jury that police assign the most inexperienced cops to the city’s highest crime areas. Liang was an officer for 18 months before the shooting.

Prosecutor Marc Fliedner said Liang never tried to help Gurley after shooting him.

“A police officer – this police officer – and he never even knelt down and try to fix what he’d done,” Fliedner said Monday.

According to grand jury testimony by Liang’s partner, Liang repeatedly told him, “It went off by accident” and fretted that he would be fired. The two then bickered for at least two minutes about which one should call a supervisor to report the discharge.

After the gun went off, Liang “stood there whining and moaning about how he could get fired,” Fliedner said.

Prosecutors allege Liang acted recklessly in his handling of his weapon and that he and his partner did nothing to help Gurley, even after they knew he had been shot. Court papers describe the pair walking around the dying victim and down a flight of stairs as the weeping friend tried to give him CPR.

A 911 call from a building resident seems to allege that police did not help, CBS2’s Lou Young reported. The caller relayed CPR instructions to Gurley’s girlfriend, Melissa Butler, who was also on scene at the time of the shooting:

9-1-1 Operator: Tell her to pinch his nose, put her mouth on top of his and breathe into his mouth.

9-1-1 Operator: Let me ask you something, are the cops assisting her?

Caller: They’re right here. They’re not with her. They’re trying to call back-up? I don’t know.

9-1-1 Operator: Does she have anybody else with her?

Caller: No, she’s alone with him. She’s still doing CPR with him right now.

9-1-1 Operator: I’m sending a message to hurry up.

Caller: Yeah, he’s not breathing.

The defense also has suggested that Liang’s gun was defective.

The slaying recalled two others by officers patrolling Brooklyn housing projects — the shootings of 19-year-old Timothy Stansbury on a rooftop in 2004 and of 13-year-old Nicholas Heyward Jr. while carrying a toy gun. Neither officer was charged.

Gurley’s family has brought a wrongful-death lawsuit on behalf of his estate and his young daughter. At an announcement of the suit in May, the girl’s mother, Kimberly Ballinger, vowed to “be in court every time to make sure that justice for him is kept, that justice for him is received.”

Gurley had planned to move the child and her mother with him to Florida, where his own mother lives, before his life was cut short, his aunt said.

“It’s how Akai was killed that’s impossible to accept,” Peterson said. “We’re still in shock.”

Liang faces up to 15 years in prison if convicted.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)