After leading authorities on a nearly three-hour pursuit by car and horseback, Francis Pusok was lying face down in the dirt with his hands clasped behind his back as San Bernardino County Sheriff's deputies moved in.
Then the "feeding frenzy" began, as one police tactics expert put it.
One deputy kicked Pusok hard in the groin area while another punched him in the head, a video by a TV news helicopter showed. Both deputies began pummeling him. More deputies arrived at the scrum, and the blows continued to rain down for about a minute before Pusok, 30, was finally handcuffed.
The scene on the chaparral-covered hillside in Apple Valley on Thursday was a vivid reminder of how a pursuit's end can turn violent. Both the suspect and the pursuing officers are in full adrenaline mode, increasing the odds the incident can turn ugly.
Since the beating of Rodney G. King by Los Angeles police officers at the end of a chase more than two decades ago, law enforcement agencies have worked to improve tactics with hopes of better controlling how officers act during those flashpoint moments.
Most chases end without incident. But there continue to be violent moments that are amplified because pursuits are often covered live by television news helicopters.
Last year, the city of Los Angeles agreed to pay $5 million to the family of an unarmed man, Brian Newt Beaird, who was fatally shot after leading police on a wild pursuit in his silver Corvette. The pursuit was televised live, and Beaird's horrified father watched as his son was shot to death.
Some high-profile pursuits have resulted in policy changes.
After an LAPD officer was shown on television striking car theft suspect Stanley Miller 11 times with a large metal flashlight in 2004, then-Chief William J. Bratton replaced the flashlights with smaller rubberized versions.
The next year, officers fatally shot a 13-year-old who led them on a short car chase in South L.A.. The LAPD responded by prohibiting officers from shooting at moving vehicles unless a deadly threat exists.
The infamous King beating in 1991, which was captured by an amateur camera operator, led to training that restricted when and how officers use their batons.
But such rules can only go so far when officers are pursuing drivers who are putting lives at risk.
"It is difficult to manage your adrenaline," San Bernardino Sheriff-Coroner John McMahon said Friday at a news conference in which he announced that the 10 deputies involved had been put on administrative leave.
"It is very difficult at times to control your emotions, control your adrenaline, but that's not an excuse for what occurred yesterday."
Ed Obayashi, an Inyo County sheriff's deputy and police use-of-force expert, described the Apple Valley incident as "a case of contagious force."
"One deputy does it so another deputy does the same.… You have multiple continuous blows here," he said. "During any pursuit, everyone experiences an adrenaline rush. But peace officers are trained to control themselves. You've got to keep your mind on the job and use your training and experience."
Charles "Sid" Heal, a retired Los Angeles County sheriff's commander, said the deputies appeared unaware that a KNBC-TV chopper hovered above, recording their actions. Heal said deputies who weren't even involved in the initial encounter later piled on.
"It went on way too long," he said. "They took what we call cheap shots."
McMahon urged the public to be patient during the investigation but conceded that the video was troubling.
"I am disturbed and troubled by what I see in the video," he said. "It does not appear to be in line with our policies and procedures."
McMahon said the deputies' use of force appeared to be excessive, though there were points in the video when Pusok appeared to struggle, possibly moving his hands and kicking in resistance.
The FBI has opened a civil rights investigation, a representative said Friday, while the Sheriff's Department has launched a disciplinary investigation as well as an investigation that could lead to possible criminal charges. The evidence to be reviewed will include audio recorders worn by the deputies.
McMahon said he would not release the names of the deputies, who include a detective and a sergeant, until the department assesses the potential threats against them. Pusok was treated at a hospital for abrasions and bruises before being booked for felony evading, horse theft and possession of stolen property, as well as an outstanding warrant for reckless driving.
Pusok is white. Of the 10 deputies, eight were white, one was Latino and one was African American, according to the Sheriff's Department.
The incident began shortly after noon on Thursday, when deputies went to a house in an unincorporated area of Apple Valley to serve a search warrant in an identity theft case. Pusok, who was in a car nearby, was not a suspect in the case, but he fled at the sight of the deputies, who pursued him.
After abandoning the vehicle, he stole the horse from a group of equestrians near Deep Creek Hot Springs. The horse was injured as Pusok urged it over the rugged terrain, sheriff's officials said.
Pusok was known to the Sheriff's Department. He pleaded no contest to felony attempted robbery in a 2006 incident as well as to several misdemeanor charges, including disturbing the peace and animal cruelty. In December, he was charged in San Bernardino County with a misdemeanor count of resisting arrest, pleading no contest.
On a prior domestic call, Pusok threatened to kill a deputy sheriff and shot a puppy in front of his family members, McMahon said.
Pusok has three children, and his girlfriend, Jolene Binder, is pregnant with a fourth. Pusok's mother, Anne Clemenson, called for the deputies who beat her son to be fired.
"I want them done," Clemenson said. "I've always thought that police are to serve and protect, and what they did ... it was not called for."
The ACLU of Southern California recently filed a lawsuit against the San Bernardino County Sheriff's Department seeking more information about use of force incidents, particularly those involving stun guns.
Adrienna Wong, staff attorney for the ACLU of Southern California's Inland Empire office, said four incidents in which people died since 2008 following the deployment of stun guns "raised a red flag" and led her office to begin investigating.