SAN JOSE — The cellphone video, taken last weekend, shows a disturbing but all-too-familiar scene: Police surround a man, beating him with a baton and fists. The person who posted it online added a comment that further outraged its wide online audience, saying the man had died as a result of the beating.

In fact, the man was booked into jail, very much alive. And now police are pointing to the incident and resulting online storm as an example of how exposure on social media sometimes muddies public understanding of police tactics rather than bringing injustice to light. In this case, they say, the man attacked officers with a bottle before the camera started recording and continued to struggle and fight even after he was pinned to the ground and handcuffed.

“All we’re seeing here is a small portion,” SJPD spokesman Sgt. Enrique Garcia said. “We have nothing to hide about this particular incident. An investigation will be conducted, and this will be presented in court. That’s the process people should respect instead of trying to make a judgment before all the evidence is introduced.”

Law enforcement officials are finding such arguments difficult to make in the current national context, amid highly publicized cases — some recorded, some not — that seem to point to gross abuses of police power.

The most notorious of those, the infamous April 4 shooting of Walter Scott in North Charleston, South Carolina, led to a murder charge against Officer Michael Slager after a bystander’s cellphone video helped convince prosecutors that Slager lied about Scott taking his Taser, the purported threat he asserted to justify fatally shooting Scott in the back as he ran away.

But other times there may be more to an incident than a video reveals. In December, a cellphone video showed police swarming a fan during the Arizona-Oregon football game at Levi’s Stadium as bystanders chanted “he’s not fighting back.” But Santa Clara police later said that before the portion of the incident caught on video, witnesses in the stands reported the man was drunk and belligerent, and he refused to cooperate with stadium staff and police.

The most recent San Jose incident started as two officers patrolling together in the area of Story Road near South White Road about 8:45 p.m. Saturday spotted a man who, upon seeing them, ran toward some bushes and ducked down. The officers thought they saw the man throw something away, so they got out of their car and approached him.

The man ran, and the officers chased him into the intersection, where they say he tried to hit one of them with a bottle, sparking a fight that ended with the officers calling for backup.

The video captured by a bystander — and posted on Facebook by a relative of his and subsequently shared by more than 7,000 users as of Tuesday afternoon — starts as two officers hold the man on the ground, and they’re soon joined by several other officers. At one point, an officer hits the man with a baton and another hits him with a fist.

Garcia said the man fought with officers during the entire encounter, tried to keep them from handcuffing him and was violent when initially put in the back of a patrol car, prompting them to enlist paramedics to strap him to a gurney. The man, identified as 22-year-old San Jose resident Juan Manuel Moreno-Lopez, was taken to the hospital, treated for bruises and scrapes and released to authorities. He was booked into the Santa Clara County jail on suspicion of assault with a deadly weapon, resisting arrest, being under the influence of a stimulant, possessing methamphetamine and destroying evidence.

One officer suffered a sprained knee and another suffered a sprained hand, Garcia said.

Police did not recover anything from the spot where Moreno-Lopez was thought to have tossed something in the bushes, Garcia said.

The Rev. Jethroe “Jeff” Moore, president of the San Jose chapter of the NAACP, saw the video and was not swayed by the police explanation.

“It was still excessive. After you have the guy down on the ground, why are you still hitting him?” Moore said. “The video is really important. What they’ve been telling us and what the video is showing is different. In every case, we’re told, ‘he was resisting.’ We’re tired of hearing that.”

LaDoris Cordell, the city’s Independent Police Auditor, said she received at least two formal complaints about the encounter, which have been forwarded to the police department’s Internal Affairs division for an investigation. She declined to comment specifically on the case but said it was an example of how video is altering the police landscape and bolsters her push for the department to adopt body-worn cameras.

“Ordinarily, there would not be any documentation,” Cordell said. “We don’t know what preceded it, but what we do know is what happened on the ground. Had officers had body cameras on, we would have seen it up close and personal.

“Police should welcome any videos people take of them when they’re in public. If they’re behaving, it’ll just confirm that.”

Dennis Kenney, a professor at John Jay College of Criminal Justice in New York and an expert in police training, agreed that police perception is suffering because of the visceral images produced by the interactions.

“Police are coming to grips with a world where everything’s being videotaped, and their brand is being hurt pretty badly at this point. They’re guilty until proven innocent, and that’s really problematic,” he said.

But Kenney also said citizens recognize the need for police use of force, as long as the conduct is accompanied by openness.

“The problem comes not in the application of force, but whether it’s done correctly,” he said.

Garcia, the police spokesman, said officers often are being judged by only what is seen in video snippets, without a full appreciation of what they have to account for.

“The average citizen will comply with an officer’s request or lawful order. If someone is under the influence, such as this person, the public doesn’t always understand what we have to deal with,” Garcia said. “If he’s willing to take on police, who else is he going to injure? Then that could be seen as our failure to take action.”

Staff writer Katie Nelson contributed to this report. Contact Robert Salonga at 408-920-5002. Follow him at Twitter.com/robertsalonga.