A Sanford man was arrested after assaulting his parents and causing a standoff on Friday, according to the Sanford Police Department.

Garth Johnson, 21, who lives with his parents on Grammar Road, was charged with domestic violence and aggravated assault. At 1 a.m., Johnson’s stepfather called police to report that Johnson had punched him repeatedly before closing himself off in his bedroom, where he had access to a gun.

Police evacuated the stepfather, who was treated for a fractured rib and a lacerated finger, and Johnson’s mother from the house and tried unsuccessfully to communicate with Johnson by phone and a public address system.

The Southern Maine Special Response Team was activated at 10:30 a.m. The team shut down Grammar Road and established a perimeter around the home as they communicated with Johnson over a loudspeaker. Johnson appeared in the doorway and was taken into custody without incident, police said.

He is being held at the York County Jail on $20,000 bail. He is expected to appear in court Monday.