An 18-year-old Geyserville man was arrested Tuesday after allegedly punching an 16-year-old boy in the face and slamming him to ground before taking his backpack in a Larkfield neighborhood.

Dominic Morrison, 18, was booked into Sonoma County Jail on suspicion of felony robbery and assault, according to a statement from the Sonoma County Sheriff’s Office.

The victim told deputies in an interview at a local hospital that he had gotten off the school bus when a silver Audi pulled up next to him near Old Redwood Highway and Cambria Way. Morrison got out of the car and asked the teen if he was in a gang, deputies said.

After the teen denied being in a gang, Morrison punched him in the face “several times,” and pushed him to the ground in a random attack that dislocated his shoulder, according to the sheriff’s office. Morrison took the teen’s backpack and left in the Audi.

Deputies pulled the Audi over on Old Redwood Highway near Fountaingrove Parkway and arrested Morrison after he was found with the backpack. It was unclear if the incident was gang-related, spokesman Spencer Crum said.

You can reach Staff Writer Hannah Beausang at 707-521-5214 or hannah.beausang@pressdemocrat.com. On Twitter @hannahbeausang.