NYPD Officer Peter Liang is charged with manslaughter for the fatal shooting of unarmed Akai Gurley in a Pink Houses stairwell. View Full Caption Pool/Byron Smith

NEW YORK CITY — The NYPD is phasing out programs that pair rookie officers together to eliminate the possibility that two inexperienced officers could wind up on a vertical patrol as Officer Peter Liang did when he shot and killed Akai Gurley.

Liang was convicted Thursday of manslaughter for fatally shooting the unarmed Gurley during a vertical patrol with another rookie officer in a stairwell of the Pink Houses. Liang testified he had his gun drawn because he was fearful of the darkened stairwell and accidentally fired his weapon when he “heard something.”

But even before this fatal November 2014 encounter, NYPD brass under Commissioner Bill Bratton had identified the pairing of rookies as a ticking time bomb, and were undoing strategies such as “Operation Impact” that routinely deployed new officers fresh out of the Police Academy to high crime posts — often together.

“We are moving out of Impact because the issue was that these cops were put together without ever having experience or training with more seasoned officers,” a source familiar with the NYPD’s new initiative explained.

New officers now work in radio cars with more experienced veterans to respond to a wide variety of radio calls across all three police shifts to get acclimated to police work and its potential dangers.

“When they come out now from the academy, they get a field training officer who they work with for six months on patrol, handling all the aspects of the job, not just working in 'Impact' zones without any real experience,” the source pointed out.

The NYPD is moving toward “Neighborhood Based Policing” with officers remaining in their communities responding to all types of calls for assistance — and not merely planted on fixed “Vertical Patrols” or “Impact” posts.

“This began when Bratton first came back and they have been reversing and unraveling the programs, but you have to do it slowly and integrate them into commands and within the right model,” the source said, adding that the entire changeover should be complete by the summer.

“The issue was that officers such as Peter Liang were put out together without ever learning enough of the job,” the source said.

Edward Mullen, president of the Sergeants Benevolent Association, has called upon the commissioner to halt vertical patrols and re-evaluate its use.

But for now Bratton has said he believes vertical patrols are an essential part of policing and he is not weighing reversing the strategy.