AUGUSTA — A Pittston man formally pleaded not guilty Thursday to an indictment charging him with manslaughter in a September 2015 all-terrain vehicle crash that killed 18-year-old Halee Cummings.

Alexander J. Biddle, now 23, was driving a Polaris 850 ATV in 2015 when it went off a driveway and into a ditch, striking several trees and ejecting and killing Cummings not far from her home in Sidney.

While the crash was Sept. 18, 2015, Biddle was not indicted until July 2017. The district attorney’s office filed the initial complaint against Biddle 13 months after the crash.

Manslaughter is a Class A crime in Maine, punishable by up to 30 years imprisonment and/or a $50,000 fine.

On Thursday at the Capital Judicial Center, Biddle was accompanied by his attorney, Pasquale Perrino.

Perrino previously described it as “a terrible accident.”

About a dozen members of Cummings’ family were in the courtroom to watch Biddle enter his plea. After the brief hearing, they met with the prosecutor, Deputy District Attorney Paul Cavanaugh, and then declined to speak to a reporter.

Biddle sat with three people who left with him.

Cummings was pronounced dead at the scene, while Biddle was treated for injuries at MaineGeneral Medical Center in Augusta.

A spokesman for the Maine Warden Service, which was investigating the crash, said at the time that “alcohol and speed” were believed to be contributing factors to the crash.

At Biddle’s initial court appearance in December 2016, another prosecutor, Assistant District Attorney Michael Madigan said the facts of the case indicate that Biddle was “driving in a roadway and saw what he believed was a cruiser and took evasive action.” Madigan added, “Reckless conduct following that is what led to this accident.”

Another group of friends was riding an ATV behind Cummings and Biddle and came across the crash. Biddle was described as a friend of Cummings’ brother.

Cummings’ mother, Jami Paquette said previously that Cummings was on her way home with some friends on a trail through the woods to Shepard Road, where her father, Hardy Cummings, has a house. Her daughter had a horse race scheduled the next morning and wanted to get to bed so she could get up early.

Cummings is buried on a small hill overlooking the family’s dairy farm.

The Cummings family started an annual barrel-racing competition in Cummings’ memory because she was an accomplished horse-back rider.

Biddle is next scheduled to be in court in November. In the meantime, he remains free on bail with conditions prohibiting him from operating an ATV, among other things.