While his mother and sisters sobbed, William Dong remained quiet during his brief appearance Tuesday in Milford Superior Court.

The 23-year-old Fairfield man let his lawyer, Frederick Paoletti, enter the not guilty pleas to weapons charges stemming from Dong's arrest last Dec. 3 at the University of New Haven campus.

Dong listened as Judge Frank Iannotti set Feb. 13 for his next court appearance.

And he remained silent, quickly waving to seven family members in the courtroom's back row, as judicial marshals took him away, back to his cell at the Garner Correctional Institution in Newtown.

"This has been a difficult adjustment for him, and it's been very hard on his family," said Paoletti.

Dong, a UNH criminal justice student who lived with his family on Stratfield Road, was arrested on campus last month after a homeless woman reported seeing him leaving a parked car with two handguns. She called 911 from a Shop Rite supermarket, and police said they found a Bushmaster assault rifle in Dong's car parked in the supermarket's lot. The gun is the same type used by Adam Lanza to massacre 20 first-graders and six employees at Sandy Hook Elementary School on Dec. 14, 2012.

Police arrested Dong without incident, but the university and several nearby schools were locked down for several hours.

Ansonia-Milford State's Attorney Kevin Lawlor is prosecuting Dong on state charges of breach of peace, illegal possession of an assault weapon, illegal transportation of an assault weapon and weapons in a motor vehicle. Dong's Bond was set at $500,000.

Last week, acting U.S. Attorney Deirdre Daly announced that her office also has charged Dong with the federal violation of transporting the Bushmaster rifle from Pennsylvania, where he purchased it in September, to Connecticut, where the weapon is banned.

That investigation involved Fairfield police and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

Meanwhile, the University of New Haven has set up a charitable fund to aid the homeless woman who alerted police to the incident involving Dong.

So far more than $23,000 has been raised, according to the university. To contribute, visit: www.newhaven.edu/goodsamaritan/make-a-donation