A 17-year-old student was held on $25,000 cash bail for allegedly bringing a loaded gun to school with him yesterday, Suffolk County District Attorney Daniel F. Conley said.

BRENDAN CAMPBELL (D.O.B. 8/15/92) of Roxbury was arraigned in East Boston District Court today on charges of unlawful possession of a firearm, unlawful possession of ammunition, unlawfully carrying a loaded firearm, unlawfully carrying a firearm on school grounds, unlawful possession of a firearm with a defaced serial number, and trespassing.

Assistant District Attorney Brenna Flynn told the court that Boston School Police responded to East Boston High School yesterday after Campbell was seen entering the building through a side door at about 12:30.

When the officers approached Campbell outside the cafeteria and said he had to speak with a school administrator, he allegedly slapped his palm against his forehead and sighed. The officers also detected the odor of marijuana coming from Campbell’s person.

The officers brought Campbell to the school police office for a search in light of his entry through an unauthorized door. They asked if he had any drugs or weapons on him. Campbell allegedly became very nervous and began to make statements about smoking marijuana. The officers stopped him and read him his Miranda warning. Campbell allegedly became extremely upset, responding in a manner the officers thought disproportionate to his admissions of marijuana use.

The officers became concerned that Campbell might have a weapon in his bag. When they attempted to pat it, he allegedly gripped it close to his body until the officers took it from him, laid it on a desk, and patted it down for weapons. At that point, Campbell allegedly stated, “I just have a little gun.”

One of the officers could feel the outline of a handgun inside the bag. Campbell was handcuffed and told the officers which pocket it was in. The officers recovered a .25 caliber semiautomatic Raven Arms handgun from that pocket.

“Be careful,” Campbell allegedly said. “There’s one in the pipe.”

Police soon found that the firearm was loaded with six rounds in the magazine and one in the chamber. The serial number had been obliterated.

Campbell was taken into custody for the firearm and given a civil citation for a partially-burned marijuana cigarette found in his pocket during the booking process.

Campbell was represented by attorney Michael Cerulli. His case will be prosecuted in the Suffolk County Gun Court, where he is due back on June 20. If he posts bail, he must wear a GPS device and is banned from Boston Public School property.