Johnny Hurley was hailed by police as a hero for shooting and killing a gunman they say had killed one officer and expressed hatred for police in a Denver suburb. But when another officer rushed in to respond and saw Hurley holding the suspect’s AR-15, he shot Hurley, killing him, police revealed Friday.

The disclosure helped clarify what happened on Monday when three people — Hurley, Arvada Police Officer Gordon Beesley and the suspected gunman, Ronald Troyke — died in a string of shootings in the historic downtown district of Arvada, an area with popular shops, restaurants, breweries and other businesses about 7 miles (10 kilometers) northwest of downtown Denver.

According to a timeline and video released by police, Troyke, 59, ambushed Beesley after he pulled his truck into a parking spot near Beesley’s patrol car as Beesley was responding to a report of a suspicious person.

The video shows Troyke running toward Beesley down an alley. When Beesley turns around, Troyke raises his gun and fires at him as two people stand nearby, police said. Beesley falls to the ground in the video.

According to the video, apparently from a surveillance camera, and a police narration of it, Troyke grabs an AR-15 rifle from his truck and is carrying it when Hurley confronts him and shoots him with a handgun. When another officer arrives, Hurley is holding Troyke’s AR-15 and the officer opened fire, police said.

Hurley’s shooting of Troyke and the officer’s shooting of Hurley are not shown on the video.

Police had not previously confirmed Hurley’s role or said who shot him. In the video posted Friday, Police Chief Link Strate described Hurley as a hero whose actions likely saved lives. He didn’t offer an apology but called Hurley’s death by a responding officer “equally tragic” to Beesley’s killing.

“The threat to our officers and our community was stopped by a hero named Johnny Hurley,” Strate said. “Johnny’s actions can only be described as decisive, courageous and effective in stopping further loss of life.”

In a separate statement, the Arvada Police Department said: “Finally, it is clear that the suspect bears responsibility for this tragic sequence of events.”

The unnamed officer’s shooting of Hurley is being investigated by a team of other area law enforcement officers led by the district attorney’s office. The district attorney will use the findings to decide whether the officer was justified in using deadly force or whether the officer should be charged with a crime.

That officer has been placed on administrative leave pending the investigation.

Police say Beesley was targeted because he was an Arvada police officer. The department on Friday released excerpts from a document written by Troyke in which he said he planned to kill as many Arvada police officers as he could, seeing his actions as a way to hold police accountable.

“We the people were never your enemy, but we are now,” it said.

About 40 minutes before the shootings, Troyke’s brother called police asking for them to check on him because he said his brother was going to “do something crazy.” Beesley and another officer tried finding Troyke at his home near downtown but were unable to, police said.

A teenager then called police to report a suspicious person — an older man who walked up, made a weird noise and showed him a condom. That’s the call Beesley was responding to when he was shot and killed.

Hurley’s family issued a statement late Friday saying they were thankful for support from the city and police and were waiting for the outcome of the third-party investigation into the shooting that killed the 40-year-old.

A witness had said this week that Hurley was shopping in the area on Monday when he heard gunshots and ran out to confront the shooter with his own gun.

“He did not hesitate; he didn’t stand there and think about it. He totally heard the gunfire, went to the door, saw the shooter and immediately ran in that direction,” Bill Troyanos, who works at the Army Navy Surplus store in downtown Arvada, told Denver news station KMGH-TV.

Troyanos said he heard Hurley fire five or six shots. The gunman fell against a parked vehicle, he said.