A California police chief who was disturbed to hear reports of a Sikh man beaten in a robbery attempt later learned that his 18-year-old son was a suspect in the crime.

Union City Police Chief Darryl McAllister took to Facebook Wednesday, where he wrote a heart-wrenching open letter to his city's residents to inform them of the allegations against his son, Tyrone Keith McAllister. The police chief said he was "completely disgusted" to have to share that his son, who is estranged from the family, was suspected of kicking and spitting on Sahib Singh Natt, 71, as he walked near a park in Manteca, about 60 miles east of Union City.

The entire attack, which made news across the U.S. and internationally, including in Natt’s native India, was caught by a security camera outside a nearby residence.

"Words can barely describe how embarrassed, dejected and hurt my wife, daughters and I feel right now," McAllister wrote. "Violence and hatred is not what we have taught our children; intolerance for others is not even in our vocabulary, let alone our values. Crime has never been an element of our household, our values, nor the character to which we hold ourselves."

McAllister wrote that he and his wife worked with investigators in Manteca to track down their son. Tyrone McAllister and another suspect, a 16-year-old boy, were arrested around 10 a.m. Wednesday morning.

The San Francisco Chronicle reported that both suspects are charged with attempted robbery, elder abuse and assault with a deadly weapon. Tyrone McAllister is being held in the San Joaquin County Jail, while the juvenile is at the county's juvenile detention center.

Manteca police officials said that Natt was on a walk around Greystone Park at 6 a.m. Monday when he was approached by two assailants, one wearing a dark hoodie and the other wearing a light-colored one. The surveillance footage from across the street shows them talking to Natt, who investigators said does not speak English.

After a few moments, Natt puts his hands in the air. The suspect in the dark-colored hoodie then kicks him in the midsection, knocking him down.

Natt gets up and tries to fend off his attacker, at which time the man in the dark hoodie delivers another kick, driving the man, once again, to the ground, where he hits his head on the asphalt.

As Natt lies on the ground, appearing to writhe in pain, the men walk out of the camera’s view. The man in the dark hoodie hurries back to the prone man and delivers another three kicks to his body.

As he walks away again, he turns and spits on the victim.

See the video of the attack on Sahib Singh Natt below.

The Chronicle reported that Darryl McAllister helped investigators identify his son as the man in the dark hoodie.

"(Tyrone) now faces serious felony charges for which, if convicted, he stands to spend a considerable about of time in prison," McAllister wrote on Facebook. "My family is shaken to the core."

The chief wrote that one of his daughters has a corporate career and the other is about to begin law school.

"It's difficult for us to comprehend how one of three kids who grew up with the same parents, under the same roof, with the same rules and same values and character could wander so far astray," he wrote. "We simply don't know why, or how we got here."

Meanwhile, the Manteca community has rallied around Natt, who attended a gathering Tuesday night at Greystone Park, just feet from where he was attacked. CBS Sacramento reported that he was the recipient of many hugs and prayers.

Randy Lee, the resident who found Natt lying in the street Monday, called the attack an outrage.

"It's just maddening to see young punks beat up an old man for no reason," Lee told the news station. "I knew he couldn't be left alone. My goal was just to get him to his house."

Natt’s daughter, Rupinder Kaur, said she was grateful her father, who already suffered paralysis on the left side of his body, is alive. The man’s son-in-law, who said Natt still has pain in his shoulder and back, called the arrests good news.

"The Manteca police do a really, really good job and all, the Manteca mayor and everybody, do a really good job and that's really good for us and all of our community," Manjit Singh Virk told the CBS station.

Manteca police officials said Tuesday that the attack did not appear to be a hate crime since robbery was the suspected motive. Department spokesman Sgt. Stephen Schluer told the Chronicle that Natt, through an interpreter, told investigators that the assailants "asked him for some type of money" before the beating began.

Natt is the second Sikh man to be attacked in less than a week in California. CBS Sacramento reported that Surjit Malhi, 50, was placing campaign signs in neighboring Stanislaus County July 31 when he was accosted by two men.

"As soon as I saw them, they threw sand in my eyes," Malhi told the news station.

They then beat him in the head, shoulders and neck, shouting, “Go back to your country” as they did so, Malhi said. He said that his turban, which likely caught the men’s attention, was what saved him by softening the blows to his head.

The men also spray-painted their angry imperative on Malhi’s yellow truck. Photos of the truck showed that the graffiti included a white supremacist version of the Celtic Cross that is also part of the logo for Stormfront, a well-known white supremacist website.

Malhi, who is active in his community and a member of the Republican Party, described himself as “American 100 percent.”

"They say go back to my country? This is my country," Malhi said.

No arrests have been made in that case.