(Adds FBI to investigate)
By Steve Gorman
LOS ANGELES, April 10 (Reuters) - A Californian sheriff has suspended 10 officers involved in the videotaped beating of a suspect who appeared to have surrendered and was lying on the ground after making a failed getaway attempt on horseback.
John McMahon, sheriff of San Bernardino County, said at a news conference on Friday he was "disturbed and troubled" by what he saw in the footage, shot from a KNBC-TV news helipcopter on Thursday near the town of Apple Valley, east of Los Angeles.
"It appears to be excessive to me based on what I saw in the video," he said of the force used in restraining the suspect, Francis Pusok, 30, after the man had already been shot by a Taser stun gun and was splayed face down on the ground.
The FBI said it had opened an investigation into the incident and the results would be referred to federal prosecutors, the San Bernardino Sun newspaper reported.
The footage surfaced on Thursday just two days after a video emerged of a South Carolina policeman fatally shooting a man as he ran away after being stopped for a broken tail light.
Ten officers involved in the beating of Pusok have been placed on paid administrative leave pending a special investigation of the incident, the sheriff said.
McMahon said Pusok was treated at a local hospital for abrasions and bruises, then jailed on several criminal charges, including felony evasion and possession of stolen property.
Pusok initially drove off in a car when officers arrived at a residence to serve a search warrant as part of an identity-theft investigation, McMahon told reporters.
He ditched the car, ran a short distance on foot and stole a horse before deputies in off-road vehicles and helicopters closed in on him in the rugged, hilly terrain outside the town.
The video shows Pusok riding the horse, falling off, scrambling to his feet, then throwing himself to the ground with his arms outstretched as two deputies run up with Tasers drawn.
The two deputies are seen pouncing on Pusok, taking turns repeatedly punching and stomping on him while several more officers join in, delivering repeated blows and kicks in a beating that goes on for at least two minutes.
McMahon said the Taser apparently was ineffective against Pusok because of his loose clothing.
Two deputies were treated for minor injuries and released, the sheriff said. (Additional reporting by Curtis Skinner in San Francisco; Editing by Louise Ireland)