San Bernardino County Sheriff John McMahon has ordered an investigation into what appears to be the beating of a surrendering suspect by several deputies after a High Desert pursuit.

An NBC News helicopter captured video of deputies taking 30-year-old Francis Jared Pusok of Apple Valley into custody on Thursday.

On the video, several deputies can be seen kicking and punching Pusok while he was lying on the ground in an apparent attempt to surrender.

“The video surrounding this arrest is disturbing,” McMahon said in a prepared statement late Thursday, “and I have ordered an internal investigation be conducted immediately.”

“In addition,” he also said, “members of the Specialized Investigations Detail are responding to conduct the criminal investigation.” They will review “the totality of the incident,” including the internal investigation and the criminal investigation.

“Sheriff McMahon is confident that they will conduct a thorough, unbiased investigation,” said Cindy Bachman, a sheriff’s spokeswoman, at a news conference Thursday evening.

She declined to comment on specifics of the video.

She said she did not know Pusok’s condition, only that he was hospitalized.

McMahon went to a hospital to check on three deputies who were injured during the incident. No deputies are on administrative leave at this time, the sheriff said, because it’s still too early in the investigation.

Sheriff’s officials said deputies from the Victor Valley station in Victorville went to a home in the 25000 block of Zuni Road in unincorporated Apple Valley shortly after noon to serve a search warrant related to an identity theft investigation. When deputies showed up, Pusok fled in a vehicle, they said.

Deputies pursued Pusok through unincorporated Apple Valley and Hesperia, authorities said. Then he abandoned the vehicle near Bowen Ranch and ran.

Deputies continued searching on foot, with off-highway vehicles and with two helicopters.

Within minutes, deputies got information that Pusok found a group of people near the Deep Creek Hot Springs and stole a horse. He fled on horseback on dirt trails, through terrain that was described as “very rugged, steep,” injuring the horse.

A sheriff’s helicopter transported a team of deputies to an area near Highway 173 and Arrowhead Lake Road to help pursue Pusok. Deputies eventually caught up with the suspect, and as they approached, the horse threw him off.

A deputy tried to use a Taser on Pusok, but it didn’t work because of his loose-baggy sweatshirt, Bachman said.

An NBC News helicopter, hovering overhead, captured the arrest on video.

In the video, Pusok is in open desert when he falls off the horse after a sheriff’s helicopter swoops above him, stirring the chaparral.

He takes a couple of steps and then lies on his stomach with his arms outstretched.

As he goes down, another man, who appears to be a uniformed deputy, fires what looks like a Taser at him.

Another deputy then runs up and kicks Pusok in the head, neck or shoulder area.

The two deputies continuously strike Pusok with their hands, feet and Taser as he lies on his stomach with his hands behind his back.

More deputies then converge on Pusok and continue pummelling him.

Hector Villagra, executive director of the American Civil Liberties Union of Southern California, late Thursday applauded McMahon for quickly launching an investigation but said more needs to be done to clean up the department.

“The ACLU of Southern California (ACLU SoCal) understands that police officers are authorized to use force when reasonably necessary,” Villagra said in a statement. “However, we are deeply troubled by the video images that appear to show San Bernardino County Sheriff’s deputies beating a man after he surrendered, placing his hands behind his back.”

Three deputies were injured during the search. Two suffered from exhaustion and a third was injured when the horse kicked his back, according to Bachman. All three were transported to a hospital.

The horse also suffered moderate injuries from being ridden hard, Bachman said.

This all happened exactly eight months after a Ferguson, Missouri, police officer, Darren Wilson, fatally shot unarmed, 18-year-old Michael Brown, which led to ongoing protests. Wilson was eventually cleared of criminal charges, but the case, and other publicized police shootings, have pushed the nation into focusing on police practices.

Just this week, video emerged of a South Carolina officer shooting a man in the back as he ran away. That officer, Michael T. Slager, has been fired and charged with murder for the killing of 50-year-old Walter L. Scott.

Anyone with information about the High Desert case can contact sheriff’s Sgt. James Evans at 760-552-6800. Callers who want to remain anonymous can call the WeTip Hotline at 800-78-CRIME (27463) or leave information on the WeTip web site at www.wetip.com.

Staff Writer Doug Saunders contributed to this report.