SAN FRANCISCO >> A man who crashed a car at the Chinese Consulate earlier this month had a crossbow and arrows and swung a knife at officers before a police sergeant killed him, San Francisco police said Thursday, offering the first official details of the attack.

San Francisco police showed body camera footage from the officers who responded to the Oct. 9 attack on the consulate in a residential neighborhood in the city. The footage showed the car inside the consulate’s lobby and people rushing out of a damaged door.

San Francisco Police Acting Commander Mark Im, speaking at a virtual town hall, said Zhanyuan Yang got out of his car, where police found a crossbow and arrows, and stood against a wall. Yang was covering his face with his left arm after a security guard sprayed him with pepper spray and hiding a knife in his right hand, Im said.

Im said Yang then turned toward San Francisco Sergeant Troy Carrasco, who was the first to arrive on the scene, and a consulate security guard, and made “multiple, rapid, downward swinging motions with the knife” in their direction.

Carrasco can be seen in body camera footage touching Yang’s back and asking “Does he have a gun?” before Yang, who is rubbing his face with his left arm, turns toward Carrasco and the security guard and starts swinging a knife. The footage shows Carrasco then opens fire and shortly after shouts, “You should have told me he had a knife!”

Yang, 31, was taken to a hospital, where he died.

When asked about why there appeared to be no attempts to de-escalate the situation, San Francisco Police Chief Bill Scott said he was not going to make any judgments nor guess what the officer was thinking, but that officers are trained to prioritize stopping a threat when confronted with an active attacker.

Several people called 911, including one person who said the suspect had a gun, which dispatchers relayed to officers sent to the scene, though Yang did not have a gun, police said.

“If we believe that we have an active attacker event, we will do everything possible to stop that threat immediately so we don’t have a loss of life,” he said.

The crash was condemned by the Chinese government, which called it “a violent attack,” and by the White House. It took place as San Francisco prepared to host next month’s Asia-Pacific Economic Cooperation summit, a gathering of world leaders from Pacific Rim nations.

Police investigators have served several warrants at the San Francisco apartment where Yang lived, Scott said, but he did not identify a motive.

“Why he showed up there, what he was doing, that’s still under investigation and there’s nothing that we have at this point that I can release,” Scott said.

Sergii Molchanov was in line waiting for his turn to submit his visa documents when he said the blue Honda sedan barreled in through the main doors at full speed, barely missing him.

Molchanov told The Associated Press that the car struck a wall and the driver was bleeding from his head as he got out of the car, yelling about the C.C.P., an abbreviation for the Chinese Communist Party. Police arrived less than a minute later, another witness, Tony Xin, told KTVU-TV.

“A consulate is a place of safety and refuge where people should not have to worry about acts of violence,” said Capt. Jason Sawyer on Thursday. “This was a highly unusual event that could have easily involved many more casualties.”

The San Francisco consulate has been targeted a number of times before. Among the most serious was a fire set by a Chinese man on New Year’s Day 2014 at the main entrance. It charred a section of the outside of the building.

The man, who was living in the San Francisco Bay Area, told authorities he was driven by voices he was hearing. He was sentenced to nearly three years in prison.