A jury trial will be held in September to decide the fate of a Westbrook man serving in the U.S. Marine Corps who has been charged with gross sexual assault of a 15-year-old.

Brian Nugent, 19, pleaded not guilty in April to two counts of gross sexual assault at his arraignment in Cumberland County Superior Court. He appeared in court Thursday for a dispositional conference, where a trial was set to begin Sept. 14.

Nugent’s attorney, Gerard Conley of Cloutier, Barrett, Cloutier & Conley, did not return phone calls seeking comment.

Nugent was arrested March 25 on a warrant after being indicted by a Cumberland County grand jury for two counts of gross sexual assault. U.S. marshals took him into custody at Fort Leonard Wood, Mo., where he is currently serving in the Marines.

Westbrook detectives sought the help of U.S. marshals in order to make the arrest because Nugent was on a military base.

The charges were based on Nugent’s alleged involvement in an incident involving a 15-year-old girl that occurred this past December when he was home on leave in Westbrook. He was 18 years old at the time.

According to court documents, the girl was a longtime family friend of Nugent and had been staying at his mother’s Webb Street home with her grandmother when Nugent came home on a break just before Thanksgiving.

Nugent and the girl had been sharing a sectional sofa as a bed when the alleged assault occurred. Though Nugent initially denied having any sexual contact with the girl to police, he later admitted to it, but maintained that it had been consensual, court documents said.