For days, a 15-second video circulated on social media that alarmed Los Angeles police.
Taken from a vehicle parked behind a black-and-white police cruiser in downtown L.A., the clip opened with a view of the patrol car then flashed down to show someone holding a revolver. The person showed the gun off for the camera, then cut back to the patrol car as an officer got out and walked away.
Worried the video was a threat against its officers, LAPD officials briefed the rank-and-file about the recording, warning officers in roll call meetings to be on alert.
On Tuesday, police said that the department's robbery-homicide detectives — tasked with investigating the LAPD's more complex and high-profile cases — now believe the video wasn't a threat against officers but a promotional video filmed by an early 1990s rap group trying to earn street cred and make a comeback.
The clip, however, has already had serious consequences. Investigators have arrested one person who they say was in the car at the time and have a warrant for the man they believe was holding the gun.
Meanwhile, an attorney representing two officers who fatally shot a man Saturday night said the pair had seen the video and thought they were under attack when the man threw what turned out to be a beer bottle through their patrol car's back window.
Attorney Gary Fullerton said the video was discussed in at least two roll call meetings that the officers attended, including one the same day as the shooting. The officers were also warned that they might be ambushed from behind, he said.
"Both officers were very focused on that," Fullerton said. "When the window got blown out, they looked at each other and said, 'We're being shot at.'"
Fullerton said that after the shooting, the officers told investigators they thought they were being attacked because of the video they had seen.
The lawyer said that even if the video wasn't a threat, there are others who do want to harm police officers. He defended the officers' actions, saying it was reasonable for them to think they were being fired upon.
"Officers feel very, very vulnerable out there right now. They feel that at any moment somebody could attack them," he said. "The officers feel terrible because they were 100% convinced that the guy was shooting at them."
As of Tuesday evening, the man's name had not been released by coroner's officials, who are still trying to locate his family. He was the 18th person shot and killed by LAPD officers this year.
LAPD officials said the man walked up behind the police cruiser, which was stopped at a red light in Van Nuys, and threw a 40-ounce beer bottle, shattering the car's back window. The two officers bailed out of the car and opened fire, killing the man.
When investigators searched his body and the nearby scene, police said, they did not find a weapon.
In the days before the shooting, LAPD detectives had begun investigating the video circulating on social media.
As detectives launched their investigation late last week, LAPD Chief Charlie Beck said, rank-and-file officers were warned about the video.
"We took that very seriously," Beck told reporters. "The safety of my officers is of utmost importance to me."
Beck said detectives conducted interviews that led them to believe that the video wasn't made "as a precursor to an attack on a police officer," but by someone trying to "promote his career as a rap artist."
LAPD officials did not publicly name the group they believe was behind the video.
Beck said detectives had identified the man they believe was holding the gun in the video and had obtained a warrant for his arrest, alleging he broke the law by having a loaded gun in the vehicle. Beck did not name the man but said he had a prior conviction for the same offense.
Investigators served a search warrant at his Downey home early Tuesday and have been in contact with his attorney, Beck said.
Another person involved in the video was arrested on an outstanding warrant in an unrelated case involving a property crime, Beck said.
Follow @katemather for more LAPD news.
Times staff writer Veronica Rocha contributed to this report.