Tyrone McAllister made his first court appearance on Friday and was seen in a video smiling and waving his middle fingers in the air
McAllister, 18, has been arrested for the beating of Sahib Singh, 71
His father is Daryl McAllister, the chief of Union City Police Department
On Wednesday, the chief revealed that he helped authorities track Tyrone down
The attack took place in Manteca, California, 50 miles from where Tyrone grew up
His father has since told how he has 'lost his way' in recent months
He and his wife are 'devastated' and 'shaken' by the teenager's alleged actions
Singh, was left needing a neck brace
The son of a police chief in California charged with attacking a 71-year-old Sikh man grinned and waved his middle fingers in the air during his first court appearance on Friday.
Tyrone McAllister, 18, was seen on video giving the finger and smiling to a Fox40 cameraman, the outlet reports. He then drops his hands to his lap before throwing up his middle finger a second time.
McAllister was in court for his arraignment. No bail was set for the teen.
On Monday, 71-year-old Sahib Singh was attacked by two young men during his morning walk in Manteca, California.
The attack was captured by surveillance cameras and showed the two thugs beating the man while dressed in hoodies. One, who was wearing a black hoodie, was brandishing a gun.
Police identified him as McAllister, the estranged son of Union City Police Department Chief Daryl McAllister.
In a lengthy Facebook post on Wednesday, Chief McAllister told of his disgust at learning his son was involved after being contacted by Manteca Police Department, the investigating department.
'Words can barely describe how embarrassed, dejected, and hurt my wife, daughters, and I feel right now.
'My stomach has been churning from the moment I learned this news, ' he added.
The police chief and his wife then helped officers track his son down and arrest him.
The teen has been charged with attempted robbery, elder abuse and assault with a deadly weapon.
The other suspect is a 16-year-old male who has not been named. Singh, the victim, struggles with English and had difficulty telling police what happened to him after the attack.
He was arrested on the same charges and will be transferred to a juvenile facility after being processed.
Singh, the victim, struggles with English and had difficulty telling police what happened to him after the attack
In his Facebook post, Chief McAllister told how his son had fallen into a 'bad crowd' and had not been at the family home for months.
'My son began to lose his way a couple years ago, while he was a juvenile, running away and getting involved in a bad crowd,' he posted.
'He pretty much divorced his friends and family, associating with people none of us knew.'
'He got into trouble for some theft-related crimes and ended up spending several months in juvenile hall,' Chief McAllister added.
'As an adult, he was again arrested for a theft-related incident, and he ended up spending another three months in adult jail as a result.
'Since being released he has been wayward and has not returned to our family home for several months,' he wrote.
The police chief said he was torn between the desire to protect his child and the oath he took as a law enforcement leader.