Warning: The above videos are graphic.

SAN DIEGO – Surveillance video showing a San Diego police officer shooting and killing a homeless, unarmed man in April was released by the San Diego County District Attorney’s Office Tuesday.

In a news conference, District Attorney Bonnie Dumanis showed surveillance video, dispatcher-officer communications and transcripts from the shooting death of 42-year-old Fridoon Rawshan Nehad that occurred in the Midway District on April 30, 2015.

"We respect the court's decision to now allow the video to become public," Dumanis said.

Nehad was shot and killed in the 3200 block of Hancock Street by Officer Neal N. Browder, a 27-year veteran of the force who was responding to a 911 call that indicated a man was threatening people with a knife.

According to an investigation by the district attorney's office, Browder feared for his life when he fatally shot Nehad, who allegedly advanced on the officer in a menacing manner. It was later determined that Nehad was carrying a metallic pen, and not a knife.

After reviewing the evidence, Dumanis determined Officer Browder was not criminally liable for his actions.

The surveillance video from a nearby business has been a key piece in all of this, and is the only known video of the incident. Officer Browder was wearing a body camera, but did not turn it on.

Local media outlets, including 10News, petitioned for the video's release, contending it was a matter of public record and that the conduct of a police officer, as a public official, is subject to public scrutiny. Police contended the video was part of an ongoing investigation and should not be released.

When Dumanis declined to file charges against Officer Browder, which meant the video was no longer part of the ongoing investigation, local media involved in the petition stepped up its effort to get the video released to the public.

On Dec. 15, a U.S. District Court judge ruled the video be released to the victim's family. The judge gave the city of San Diego a seven-day period to appeal. Dumanis said Tuesday that the city and police department would not appeal the judge's decision.

According to Dumanis, the events unfolded as follows: Surveillance video showed an adult bookstore employee going into the area behind the store and encountering Nehad. About six minutes later, Nehad entered the bookstore, went up to the cash register and threatened an employee. The employee later told police he believed Nehad had a knife. The employee called 911 and told the dispatcher that Nehad had a knife. At 12:01 a.m. Nehad was seen behind a business hiding a knife sheaf behind some sandbags. Two minutes after hiding the knife sheaf, video showed him walking up to a nearby strip club, approaching the bouncer and pulling out what appeared to be the tip of a knife out of his pocket. The doorman told detectives that Nehad showed a knife, showed the tip, and put it back into his pocket. On his way to the scene, radio dispatchers told Browder that Nehad was armed with a knife. Nehad entered the alley. Browder fired his weapon 32 seconds after driving into the alley. Nehad was approximately 17 feet from Browder, based on the video. Browder fired one shot. Immediately afterwards, he began rendering first aid to Nehad.

According to his family, Nehad grew up in Afghanistan, was drafted into the Afghan army as a teenager and kidnapped by the Taliban. After his release, they sent him to Germany for 14 years for his safety before he joined them to live in San Diego. They said he was getting treatment for PTSD, but would become manic.

A records check showed Nehad had a long criminal history, including two cases in 2008 involving felony vandalism and burglary.

Not long after the incident, Nehad's family filed a claim against the San Diego Police Department alleging use of excessive and unreasonable force, and a violation of the man's civil and other legal rights.

The claim accuses Officer Browder of shooting an unarmed man and the police department of covering it up by withholding surveillance video of the shooting.

The family later filed a second claim against San Diego's police chief Shelly Zimmerman alleging she encouraged a 'code of silence' culture in the police department.

The San Diego Police Officers Association released the following statement Tuesday: "The SDPOA strongly believes that San Diego County District Attorney Bonnie M. Dumanis made the proper decision not to file criminal charges against SDPD Officer Neal Browder, after a thorough review of all the evidence associated in this matter. "