SF police shooting of wheelchair user questioned S.F. POLICE

An officer looks at the scene after police shot a man in a wheelchair who reportedly threatened them with a knife in San Francisco, Calif., on Tuesday, Jan. 4, 2011. Witnesses say the man had earlier slashed the tires of several cars parked nearby. less An officer looks at the scene after police shot a man in a wheelchair who reportedly threatened them with a knife in San Francisco, Calif., on Tuesday, Jan. 4, 2011. Witnesses say the man had earlier slashed ... more Photo: Paul Chinn, The Chronicle Photo: Paul Chinn, The Chronicle Image 1 of / 1 Caption Close SF police shooting of wheelchair user questioned 1 / 1 Back to Gallery

Use-of-force experts who viewed the video recording of San Francisco police shooting a man in a wheelchair questioned why officers moved dangerously close to the knife-wielding suspect and said an electronic Taser would have been the ideal weapon to use in that confrontation.

Tuesday's shooting outside the city's Department of Public Health building on 10th and Howard Streets occurred moments after officers responded to a 10:18 a.m. report of an agitated man puncturing car tires.

Police Chief George Gascón said the suspect, who remains at San Francisco General Hospital recovering from non-life-threatening gunshot wounds, had stabbed a responding officer in the upper left shoulder before a passer-by began video-recording the incident. Gascón also said officers used pepper spray on the man in a failed attempt to subdue him before the video started.

David Klinger, an expert on police use of force and an associate professor of criminology at the University of Missouri-St. Louis, cautioned that the video offers a two-dimensional glimpse of the incident and that it remains only "one piece of the investigation."

Yet Klinger, a former Los Angeles patrol officer, also wondered why officers closed in on a man who had already stabbed one of their own and continued to behave erratically.

"Given that officers are trained to give distance between themselves with suspects who are armed and dangerous, at first blush I'd want to know why they were getting in that close," Klinger said.

At times on the video, it appears officers stand within 5 feet of the slow-moving suspect, then about 10 feet just before the shooting.

Officers are trained to stay at least 20 feet away from agitated and dangerous suspects when no barriers exist, Klinger said.

Klinger also said the officers may have experienced perceptional distortion - a momentary loss of time and distance awareness during heightened states of perceived threat.

"They may look at that video and say, 'Oh my gosh, I thought I was much farther away from him.' Or they might say, 'I thought I was right on top of him.' "

The sensory alteration may also explain why San Francisco police initially reported the suspect was standing when he was shot, not seated as the video shows.

On Tuesday, Gascón asked that the public consider the demands of policing in a life-threatening situation before casting judgment.

During a news conference where the chief gave a moment-by-moment explanation of the video to "put it in proper context," he admitted it appeared that the suspect had thrown his knife to the ground, not toward officers.

Less than one second after the suspect's throwing motion, the officers opened fire.

"The problem is that what the officers perceive and what is occurring are two different things," Gascón said.

The video shows at least four plainclothes officers with guns drawn and two uniformed officers surrounding the suspect in his wheelchair. At least two officers involved in the shooting were placed on administrative leave, police said, and there could be more as the investigation continues.

Tuesday's shooting was the second by San Francisco police within a week's time that Gascón said could have been avoided if his department was equipped with Tasers.

On Dec. 29, police fatally shot a knife-wielding man, Vinh Bui, inside his Portola district home.

Steve Ijames, an expert in nonlethal police tactics, said that in Tuesday's shooting, a Taser would have been better suited than pepper spray or beanbag shots, which are useless against pain-averse suspects. Suspects who are incapacitated by drugs or enduring a psychotic episode often do not respond to such warnings.

"Of the few options they had, the Taser would have been the most effective," Ijames said. "The Taser locks up the body. That's why it's uniquely qualified. You don't want to hurt them, but you also don't want them throwing knives at people."

Watch the video at links.sfgate.com/ZKUO.