SAN BERNARDINO (CBSLA.com) — Authorities have launched an internal investigation after the arrest of a man accused of ditching a car and leading deputies on a three-hour pursuit on horseback in San Bernardino.

Francis Pusok, 30, was captured in footage by a news helicopter falling off a horse authorities said was stolen Thursday afternoon in Apple Valley.

Deputies say they tried to hit Pusok with a Taser, which was ineffective.

The footage then shows one of the deputies kicking Pusok in the head, another kicking him in the groin, and together they punch and knee him.

Other deputies are then seen moving in and hitting Pusok. At this point, it’s unclear what Pusok is doing, hidden beneath the group of officers.

The entire incident lasted more than a minute, according to the footage San Bernardino County Sheriff John McMahon said was “disturbing.”

McMahon has ordered an internal investigation into the arrest.

“The video surrounding this arrest is disturbing, and I have ordered an internal investigation be conducted immediately,” he said in a statement. “In addition, members of the Specialized Investigation Detail are responding to conduct the criminal investigation.”

“What I saw on the television was thugs beating up my client. That’s what I saw. And these questions about what was he doing? What did they do? This is far worse than Rodney King,” said Pusok’s family attorney Jim Terrell, who’s calling for the termination and arrests of the deputies seen in the footage.

Deputies said they were serving a search warrant to Pusok in connection with an identity-theft investigation when he fled.

“I couldn’t believe it. The first thing I said was, ‘They can’t do that.’ That is first thing out of my mouth was that, ‘They cannot do that,’ ” said Jolene Bindner, Pusok’s girlfriend of 13 years.

Bindner described Pusok as a great father but admits he’s had several run-ins with the law.

CBS2 uncovered convictions of Pusok’s dating as far back as 2002. They include: driving on a sidewalk at an unsafe speed in 2002; attempted robbery in 2006; fighting in 2011; cruelty to an animal in 2013; resisting an officer in 2013; and obstructing or resisting an officer in 2014.

“I’m not gonna stand here and say that he’s perfect, because who is?” Bindner asked.

“I want to know what these cops past records are. Did they just start being thugs or have they been thugs for years?” said Terrell, who wants the FBI to investigate the department’s handling of his client.

The department has not indicated whether the officers will be punished.

“These are bad cops whether it’s Ferguson, Missouri, or right here in Apple Valley. This stuff’s got to stop,” Terrell said.

Pusok has been hospitalized with injuries he is expected to survive, and three deputies were injured in the search, according to authorities.

Pusok’s family is also considering a civil suit.