Dylan Volk, the son of state senator Amy Volk, was arrested early Sunday morning in Scarborough on charges of felony possession of methamphetamine and driving under the influence.

Dylan Volk, 25, was taken into custody off Old Blue Point Road after someone called police to tell them that a car had gone off the road, said Detective Sgt. Rick Rouse. When officers arrived, they found Volk in the driver’s seat with the car running.

Police smelled alcohol on him, and after conducting a field sobriety test, arrested Volk on a charge of operating under the influence of alcohol, a misdemeanor.

During the arrest, officers asked him if there were any belongings in his car that he needed before he was taken to jail. He asked them to retrieve his wallet, cellphone and headphone case. In the headphone case, police said, was a rock-like substance and a straw. The substance tested positive for methamphetamine.

Volk was also charged with possession of methamphetamine, and was released from the Cumberland County Jail on $260 bail.

His next court date was not immediately available.

Rouse said Monday that officers found 0.8 grams of the suspected drug. Volk was also administered a breath test, in which his blood-alcohol level was found to be 0.06 percent or higher, said Rouse, who did not specify Volk’s blood-alcohol content.

Although the legal limit is 0.08 percent, Rouse said other factors can lead an officer to charge someone with drunken driving if the person’s blood alcohol content is below the limit.

Amy Volk is a Republican state senator from Scarborough. Reached by phone Monday, she declined to comment on her son’s arrest, and said she would release a statement later. She had not done so as of Monday night.

In 2015, Dylan’s father, Derek Volk, self-published a book detailing the family’s struggle raising Dylan, who has Asperger’s syndrome, an autism spectrum disorder.

Dylan Volk most recently lived in Austin, Texas, according to his online biography, where he has pursued a career in comedy. He maintains a YouTube channel where he broadcasts a weekly radio show, which also airs locally on WLOB.

He and his father have spoken at dozens of events and gatherings since the book was published, and have several dates scheduled in 2017 across the country and in Maine.