The man killed by a Knoxville Police Department officer on Monday died of a gunshot wound to the back, according to a document released to the family by the Knox County Regional Forensic Center.

Channara Tom "Philly" Pheap, 33, died after being "shot by law enforcement" at 5:39 p.m. in a parking lot at Clear Springs Apartments in northwest Knoxville, the preliminary forensic document states. His time of death is listed at 6:37 p.m.

Pheap's cause of death is listed as "gunshot wound of back."

The document supports the accounts of several people who witnessed parts of the confrontation between the two men.

An autopsy was performed by the Knox County Medical Examiner's Office, and the preliminary findings were available to determine the cause of death, according to the document.

Knox County Chief Medical Examiner Dr. Darinka Mileusnic-Polchan referred questions to the Knox County District Attorney General's Office. A spokesman for that office did not immediately return a request for comment Friday afternoon.

It could be months before the final autopsy report is made public.

What police have said

Authorities have released few details surrounding the shooting of Pheap, who was of Cambodian descent, by Knoxville Police Department Officer Dylan M. Williams.

The police department initially said in a statement that Williams responded to a hit-and-run in the 1700 block of Merchant Drive, near the apartment complex, then got into a fight with Pheap and ultimately shot him.

The Knox County Sheriff’s Office, citing the ongoing investigation, has declined to release additional details about the shooting, including whether Pheap was armed and where he was struck when he was shot. The sheriff’s office is investigating the shooting as part of an agreement with the police department so officers don't investigate their own.

"It is likely unless something out of the ordinary takes place that the next statement will come from the District Attorney after the investigation is completed," sheriff's office spokeswoman Kimberly Glenn wrote in an email Friday to Knox News.

What witnesses have said

Video footage taken by bystanders and posted to social media shows the moments after the shooting. Pheap is lying face down in a patch of grass next to a fenced-in dumpster, just off the road in front of an apartment building at Clear Springs. The officer, his uniform muddy, is standing nearby and walking around the body.

No video has surfaced publicly of the shooting and what preceded it. It’s unclear what, if anything, may have been captured on video by the dashboard camera in Williams’ cruiser. Knoxville Police Department officers do not wear body cameras.

Witness accounts vary, with some suggesting a struggle over a Taser before the shooting.

Takenya Hyatt, 33, said in an interview she was inside a friend’s ground-level apartment at Clear Springs when she heard two gunshots. She recalled running to the window to see an officer standing next to Pheap's body. She ran outside.

Hyatt said she approached the body and saw two bullet holes in the bloodied back of the man's shirt, one below each shoulder. She said the officer appeared emotional as he asked her and others if they saw what happened. She said no.

“I asked him, ‘Why did you shoot him?’ And he said, ‘He took my Taser and tried to tase me,'' Hyatt said, adding that she didn’t see a Taser near the man’s body.

Hyatt said she was close enough to hear Pheap take his last breath.

After being told to move back, she went inside to get her cellphone and began broadcasting video of the scene on Facebook Live. In the footage, sirens can be heard as police and paramedics arrive, cordon off the area with crime scene tape and use a sheet to shield the body from view.

"He said he took his Taser, and he shot him twice," Hyatt says in the video. "He shot him in the back, man."

Billy Johns Jr., a 44-year-old forklift operator who lives in Georgia, said he was at Clear Springs on Monday to visit the mother of his son, who lives in a second-floor apartment at the complex.

Johns said he had stepped out onto the balcony to warm up when he saw a man running diagonally across the street in front of the apartment building.

“He didn’t look scared. He didn’t look as if he was running from something,” Johns said. “But it looked like he had to be somewhere. I’m watching him run, and in the process of watching him run, the gunshots started, like 'pop pop pop.'”

Johns said he heard the gunshots as Pheap approached the dumpster in front of the apartment building. Pheap moved to the other side of the dumpster, he said, then collapsed face down in the grass there.

From his vantage point on the balcony, Johns said he could not see who had pulled the trigger and so he stayed back, fearing more gunfire. Johns estimated some 15 or 20 seconds passed before he saw a police officer move down the sidewalk toward Pheap’s body from behind.

Jones said he did not see a scuffle between Pheap and the officer.

Neither Johns nor Hyatt saw the officer fire his gun. Neither saw where he was in relation to Pheap when the shots rang out.

Family, friends hold vigil

Pheap was born in Minnesota — the fourth of nine kids — but grew up in Philadelphia. That’s how he got the nickname Philly, his brother said. The family currently lives in Rhode Island and traveled to Knoxville upon learning of Pheap’s death.

"No matter what he was by his family’s side and there to guide them through anything," reads part of a statement issued to Knox News by the family. "He encouraged his family to finish school, prepare for the future, work hard and treat each other with kindness."

Pheap had a 5-year-old daughter with his longtime girlfriend, who lives at Clear Springs Apartments. During a vigil on Thursday night, family members, friends and residents lit incense and arranged a memorial at the spot where Pheap died. The young girl, a bow in her hair, sat on the sidewalk and frowned as she looked at a photograph of her father.

Pheap also was helping to raise his girlfriend’s two young sons. He most recently listed a Knoxville address and worked for a local moving company through a temporary employment agency.

Pheap’s local criminal history includes a 2015 conviction for misdemeanor evading arrest. When a Knoxville policeman tried to pull him over for having a cracked windshield, Pheap sped away, according to an arrest warrant. Officers found him at an apartment complex, and he told them he drove away because he thought his license was suspended.

Williams, the officer who shot Pheap, was hired by the Knoxville Police Department in 2014. Authorities said Williams suffered an unspecified injury and was taken to a hospital before being released following the shooting.

Williams remains on paid administrative leave pending the outcome of the investigation by the Knox County Sheriff’s Office, which is standard procedure in shootings by officers.

Knox News has requested but not yet received Williams’ personnel file, which documents additional details about his service, including performance evaluations, departmental transfers, commendations and reprimands.

Reporter Hayes Hickman contributed to this story.

Reach Travis Dorman at travis.dorman@knoxnews.com. Follow him on Twitter @travdorman.