LEWISTON — One of two teenage boys accused of commandeering a bucket loader and taking it for a destructive joyride in September has pleaded not guilty to driving-related charges.

The second 14-year-old is scheduled for court Wednesday, where he or his attorney is expected to deny the same misdemeanor charges.

University of Maine School of Law student attorney Cailley Bonti entered not guilty pleas to the charges for Shawn Demarest of Litchfield last week on the Unified Criminal Docket in 8th District Court. Bonti is supervised by the Cumberland Legal Aid Clinic.

Demarest and Matthew Newton-Fortin of Auburn are charged with driving to endanger and failure to stop for an officer stemming from the Sept. 16 incident, during which police said the two climbed into a $10,000 bucket loader that belonged to a Richmond general contractor without permission shortly after midnight in West Gardiner.

From there, the pair drove the machine through Sabattus, running over an $8,000 sign in front of Fielder’s Choice Homemade Ice Cream, as well as plowing into mailboxes, parked cars, street signs and fire hydrants throughout Sabattus, according to police reports.

They continued south through Lewiston onto the Maine Turnpike and crossed the median, facing oncoming traffic in the northbound lanes. The bucket loader collided with a police car and a private vehicle before Lewiston officers shot at the bucket loader’s tires near the New Gloucester barrier toll, police said. The two boys were taken from the bucket loader shortly after 5:30 a.m.

Each faces eight charges in juvenile court, including attempted elevated aggravated assault, aggravated criminal mischief, attempted aggravated assault, reckless conduct with a dangerous weapon and theft by unauthorized taking. All of these charges would be felonies in the adult criminal court system.

One of two boys who had been taken to Long Creek Youth Development Center in South Portland has since returned to a group home in Litchfield. They have denied the felony-level juvenile offenses and are both undergoing psychological evaluations, according to court papers.

cwilliams@sunjournal.com