The first week of the trial for Peter Liang, the NYPD officer who shot and killed 28-year-old Akai Gurley in a Brooklyn stairwell in November 2014, rounded out with a close look at Liang's obligations under the NYPD's patrol guide, the NYCHA-run building's reputation within the NYPD, and Liang's NYPD-issued firearm.

According to testimony, Liang had just entered a darkened stairwell from the roof of the Pink Houses in East New York, with his gun out, when he fired the fatal shot. The bullet ricocheted off of the stairwell wall and struck Gurley on the seventh floor landing, one floor below. Gurley ultimately collapsed on the fifth floor.

Liang was a rookie cop with less than two years on the job when he shot Gurley. While both the prosecution and the defense agree that the shooting was accidental, the prosecution is arguing that Liang broke departmental rules by failing to immediately report the shooting or administer first aid to the dying man.

"Instead of doing all he could, Liang didn't call for help, he stood there whining and moaning," Brooklyn Assistant District Attorney Marc Fliedner said in his opening statement on Monday.

In court on Tuesday, the defense questioned two officers who responded to the stairwell minutes after Gurley was shot—Salvatore Tramontana and Andrae Fernandez. Buzzfeed reported that the defense set out to present the Pink Houses as a particularly dangerous building to patrol, and the roof of the building most of all.

The defense asked the officers how typical it was for NYPD officers to patrol with their guns drawn at the Pink Houses. Fernandez said that officers are "informally trained" to have their guns out during a vertical patrol. He also testified that the lights on the roof landing and seventh and eighth floors directly below the landing were out when he arrived on the scene—testimony backed up by video evidence shown to the jury. The video was taken a few hours after the shooting, and showed that the fifth-floor stairwell, where Gurley collapsed, was illuminated. Only the seventh and eighth floors were darkened.

On Thursday, the prosecution questioned witnesses within the department who testified that Officer Liang had received all necessary training in the police academy. Detective Nathan Garcia, whose job responsibilities include maintaining the police academy syllabus, also testified that officers are required to report any "unusual crime" to a superior, and administer medical aid as needed.

During its cross-examination, the defense had Garcia read out specific passages of the handbook, in an apparent effort to emphasize the dangerousness of the Pink Houses.

"Lower the volume on your radio and secure any loose keys or anything that could identify you, by sound, as a police officer when descending the stairwell," the guidebook reads. "Criminals, alerted to your presence by sound, would have time to escape or devise a plan, as you unknowingly walk down the stairs, for a possible ambush."

Lieutenant Vitaly Zelokov of the 75th Precinct was working overtime on the November night that Gurley was shot, and gave stark testimony on Thursday detailing Liang's inaction at the scene.

"He was frozen when I first encountered him before I took his firearm," Zelokov testified. "I took the officer out of the stairwell and into the hallway. He was shaken up, he was pale, he became unable to stand on his feet and I had to sit him down."

Asked if Liang was capable of doing police work, Zelokov said "no." Asked more specifically if Liang might have been faking this demeanor, Zelekov again said "no."

Also on Thursday, Detective Mark Acevedo, a trigger-pull and firearm expert, testified how many pounds of force Officer Liang had to exert in order to fire his gun. Acevedo performed analysis on the weapon, which was also presented in court in a plastic evidence bag.

According to Acevedo, Liang's gun required 11.5 pounds of force to fire. For comparison, a non-NYPD Glock of similar size would only require 5.5 pounds.

Liang has been charged with manslaughter, criminally negligent homicide, assault, reckless endangerment, and two counts of misconduct. The judge has scheduled final arguments for February 8.

Reporting by Max Rivlin-Nadler.