SCARBOROUGH — The son of state Sen. Amy Volk, R-Scarborough, was arrested early Sunday morning for allegedly operating under the influence and possessing methamphetamine.

Police said Dylan S. Volk, 25, of Elbridge Oliver Way, was arrested just after midnight Jan. 8 on Old Blue Point Road after someone called the Scarborough Police Department to report a car had swerved off the road.

When officers arrived, Volk was still in the driver’s seat with the car running, Scarborough Sgt. Rick Rouse said Monday morning.

According to Rouse, officers conducted a sobriety test to determine if Volk was under the influence after they smelled alcohol on his breath.

Officers also discovered what looked like “small rocks” in a headphone case with a straw inside Volk’s car, Rouse said. A lab test later determined that the substance was methamphetamine.

Volk was taken to the Cumberland County Jail. He was bailed out Sunday afternoon around 4 p.m., according to jail officials.

Sen. Amy Volk was re-elected to a second term in November in Senate District 30. She previously served two terms in the House.

Dylan Volk has been diagnosed with Asperger syndrome, and Volk, her husband Derek, and Dylan have all spoken openly about his efforts to cope with the developmental disorder that generally affects one’s ability to effectively socialize and communicate. In May, Dylan spoke about his experience at the Southern Maine Autism Conference.

Volk was previously arrested in May of 2012 on a charge of aggravated criminal mischief.