MANTECA, Calif. >> A San Francisco Bay Area police chief said his family is “shaken to the core” after his son was arrested in the beating of a 71-year-old Sikh man.

Tyrone McAllister, 18, and a 16-year-old boy could face charges including attempted robbery, elder abuse and assault following Monday’s attack in the city of Manteca. Police say they are investigating the attack as a robbery, not a hate crime, The Modesto Bee newspaper reported.

McAllister is the son of Union City Police Chief Darryl McAllister, who wrote Wednesday on Facebook that “words can barely describe how embarrassed, dejected, and hurt my wife, daughters, and I feel right now.”

The chief said his son began running away and getting into trouble about two years ago, committed several theft-related crimes and spent several months in juvenile detention. Later, as an adult, the younger McAllister spent another three months in jail, his father said.

“Violence and hatred is not what we have taught our children; intolerance for others is not even in our vocabulary, let alone our values,” he wrote. “Crime has never been an element of our household, our values, nor the character to which we hold ourselves.”

Police said Sahib Singh, who doesn’t speak English, was attacked while walking on a sidewalk next to a park in Manteca, about 40 miles northeast of Union City, authorities said.

Surveillance video shows two people in hoodies approach him. Singh appears to try to walk away, but they confront him and he puts his hands up.

The two appear to talk him briefly before one kicks him in the chest, knocking him to the ground. His turban falls off. He gets up and appears to be trying to defend himself when one of the attackers kicks him again, knocking him down. Singh is kicked several more times, and an attacker spits on him before leaving.

Singh suffered minor injuries, police said.

McAllister said he and his wife worked with Manteca police to help track down his son, who now could face felony charges and prison time.

The attack was the second on a Sikh man in a week in central California.

Last week, two men beat a man in the community of Keyes and spray-painted a neo-Nazi symbol on his truck in what police are treating as a hate crime.

Surjit Malhi said he was putting up campaign signs for local Republicans when two men ambushed him.