The bullet that killed Akai Gurley traveled through his sternum, into his chest cavity and through his heart before going through the diaphragm and then being found inside his liver, a doctor from the medical examiner’s office testified on Thursday.

Dr. Floriana Persechino said Gurley needed “expert intervention,” and simple chest compressions would not have saved his life.

“In this particular case, I don’t believe that just that would have saved this individual,” she said.

The testimony came after Officer Peter Liang’s partner said on Thursday that he didn’t feel comfortable performing CPR as Gurley lay bleeding in the stairwell of the Pink Houses in East New York. Liang faces charges of second-degree assault, criminally negligent homicide, reckless endangerment and official misconduct, in the death of Gurley on Nov. 20, 2014.

Officer Shaun Landau, 28, testified he only spent a couple minutes practicing CPR on a mannequin while in the police academy, and his memory of the training was hazy.

The entrance wound on Gurley, which was shown on a screen in the courtroom, was about 1 inch by 1/2 inch.

“He was probably bleeding but not a lot,” Persechino said. “There might not be a lot of bleeding with this type of injury externally.”

Earlier in the day, Liang’s defense attorney, Robert Brown, questioned Landau over his recollection of the length of time the rookie officers spent in the hallway being different than what he said the morning after the shooting that killed Gurley.

Landau has testified the pair, unaware Gurley lay bleeding in the stairwell below, spent about four minutes arguing over who should tell their supervisor a Liang’s gun had discharged. Landau admitted he said the pair waited 30 to 80 seconds when he was first questioned by investigators following the shooting.

“I wasn’t timing it,” he said, adding, “I was exhausted. I was pulled out of the hospital bed to go to do the interview, and I was still very very stressed out at the moment.”

The jury is expected to start deliberating on Tuesday.