The Commonwealth of Massachusetts has dropped all charges against Garett D. Trombly ’03, the Cabot House resident who was arrested by the Boston Police Department (BPD) on Sept. 9 and charged with assault and battery on a police officer, resisting arrest and drinking alcohol in public.

Court records filed by the Suffolk County District Attorney’s office last week said the prosecution decided not to pursue the case because “sufficient evidence does not exist to allow the Commonwealth to sustain its burden of proof beyond a reasonable doubt.”

Trombly said yesterday he was “relieved” to be in the clear.

“It’s reassuring that the false charges were dismissed,” Trombly said. “It proves that the system worked this time...I’m glad that this part, this phase of the whole ordeal is over.” Trombly pleaded not guilty at his Sept. 10 arraignment.

But the case may not be closed.

Trombly’s attorney, Andrew Good, has alleged that after the arrest, Trombly was the one who was assaulted. Good alleges that BPD Sgt. Harry A. Byrne Jr. hit Trombly repeatedly in the face, breaking his jaw, after Trombly was brought to the Brighton district station.

“I think that the personal injury may have added an element of urgency to the investigation,” Trombly said.

The Harvard economics concentrator spent almost a month with his jaws wired shut, but has yet to file any formal charges against Byrne or the BPD.

Trombly said he believes the district attorney’s actions were “a step in the right direction.”

“The charges were dismissed at the request of the prosecution,” Trombly said. “That would mean to me that their investigation provided insufficient credibility to the charges.”

Trombly was arrested outside of the residence of his high school friend, Boston College junior Thomas J. Davis at 2021 Commonwealth Ave. at about 1 a.m. on Sept. 9. Davis was also arrested that night for drinking publicly, underage drinking, disorderly conduct and resisting arrest.

All charges against Davis have also been dropped.

“It’s comforting to know that the legal system came through,” Davis said.

According to a police report, Byrne saw Davis, Trombly and friends drinking alcohol in public. The report states that when Byrne apaproached the group and asked them to leave, Trombly, who is of legal drinking age, spat and made offensive remarks.

Davis has denied the police report’s charges.