The incident took place on the 250 block of East Orange Grove Boulevard early Friday morning at 2:05 a.m., according to the Los Angeles County Sheriff's Department.
In the 911 call, a male caller tells the dispatcher that his brother is high and holding a knife under his armpit, but has not threatened anyone in the apartment with it.
When the dispatcher asks if his brother has any mental conditions, the caller says he doesn't know. Later he says his brother has been known to be violent.
Police say when they arrived at the scene, the man, who was black, refused to comply with officers' orders so they used a Taser to try and disarm him. That set off a fight, which ended with the man being subdued.
After the man was restrained, he stopped breathing and the police administered CPR, according to police. The man died at the scene.
While officials have yet to identify the man, Antoinette Delaney identified him as her younger brother, Reginald Thomas. Delaney was among dozens who gathered outside of building where Thomas died.
At a Friday night press conference, Pasadena Police Chief Phillip Sanchez explained his reasoning for releasing both the 911 tape and the security video.
"There have been national events recently that the video has been a flashpoint," Sanchez said. "If releasing the video reduces angst and allows the community to see what we have seen and they can draw their own conclusion based on that information. If that effort reduces the likelihood of one of my officers being injured or assaulted, as we’ve seen in Dallas or in other areas of the United States or it safeguards my public, preserves life or otherwise prevents property destruction, then I think it’s the prudent thing to do in this instance, based on the totality of these circumstances. It doesn’t suggest that the Pasadena Police Department will follow this protocol in the future."
The 911 call released by the Pasadena Police Department was actually the last of five calls made to authorities regarding this incident, according to Lieutenant Mike Rosson of the Los Angeles Sheriff's Homicide Bureau. He described the call as "a compilation of mostly the fifth call."
He said the first call was dropped. Since it was made from a cell phone, police tried to triangulate it and determine the caller's location. In the last call, the emergency dispatcher was able to get the address so police could go to the residence.
The grainy security footage shows officers arriving at the apartment complex and walking to the door of the apartment but the actual confrontation cannot be clearly seen.
Rosson also said that the during the scuffle, there were three taser deployments — but only one was effective.
"It caused the subject to drop the knife and the extinguisher and that's when the physical altercation occurred," Rosson said.
Rosson confirmed that the man's ankles were restrained and he was handcuffed, "but they were not in any way shape or form connected."
Pasadena Police Chief Sanchez said that as far as he know, there are no other videos of the incident. He says officers were not wearing body camera and that, in fact, Pasadena officers won't have body cameras until at least December 2016.
Protesters chanting and carrying signs marched through Old Pasadena on Friday night, according to the Pasadena Star News.
The peaceful protest began at the scene of the man’s death on Orange Grove Blvd. Protestors then headed to the Pasadena Police Department and City Hall for speeches. They eventually returned to the scene of the man’s death.