The former dean of an exclusive Connecticut boarding school has been charged with sexually assaulting a fourth student.

Robert Reinhardt, 44, who was fired from The Gunnery school in Washington, Conn., in June, was arraigned Tuesday in Litchfield Superior Court on charges of second-degree sexual assault and giving alcohol to a minor.

State police say the charges involve a man in his early 20s who alleges Reinhardt sexually assaulted him when he was a junior and senior at the school in 2003 and 2004.

Reinhardt already faces similar allegations involving three other former students. He pleaded not guilty to all the charges on Tuesday and is due back in court Oct. 16, his attorney, William Dow III said. He faces up to 60 years in prison if convicted.

"Rob Reinhardt continues to receive waves of support from members of the Gunnery community and beyond," Dow said Wednesday. "He denies this charge as he has the preceding three, and we're prepared to face those charges in court."

The files in the cases have been sealed, but the allegations against Reinhardt were detailed in two civil lawsuits.

They allege that Reinhardt frequently had students spend the night at his on-campus apartment, where he allegedly assaulted them.

Reinhardt, of Telford, Pa., had been a member of the faculty at The Gunnery since 1996 and was named dean in 2006. He also served as a dorm parent and coached the school's crew team.

A message was left Thursday at the school seeking comment from Head of School Susan Graham. She has not commented on the case since issuing a statement after Reinhardt was arrested in June that said the safety of the Gunnery's students was her top priority and school was taking the allegations against Reinhardt seriously.

The school, in the rolling hills of western Connecticut, was founded in 1850 by outdoorsman and abolitionist Frederick William Gunn. More than 300 students were enrolled last year, and 73 percent of them lived on campus, where tuition, room and board runs at more than $42,000 per year.