ATHOL — Two men from Athol and Needham and a woman from Weymouth were arrested Monday in Boston’s Downtown Crossing on several drug-related charges, according to police.

At around 1 p.m. on Monday, Feb. 26, the Boston Police Department’s A-1 (Downtown) Drug Control Unit placed Keith Curtis, 38, of Athol, Katherine Isaacs, 33, of Weymouth, and Michael Groden, 44, of Needham under arrest, according to a statement from the BPD.

Curtis is charged with unlawful possession of a firearm, unlawful possession of ammunition, trafficking class A and B substances, distribution of a class A substance and conspiracy to violate drug laws.

Isaacs is charged with trafficking class A and B substances, distribution of a class A substance, possession of a class B substance and conspiracy to violate drug laws.

Groden is charged with trafficking class A and possession of a class B substance.

All three suspects are scheduled to appear in Boston Municipal Court for arraignment.

According to the BPD, during a drug investigation in Downtown Crossing, officers witnessed a drug exchange involving the three individuals. Authorities seized approximately 172 grams of heroin, 48 grams of crack cocaine and nine suboxone sublingual films.

Officers also discovered a SCCY 9MM semi-automatic handgun with eight rounds of ammunition in Curtis’s black fanny bag. Curtis was also found in possession of $931 in U.S. currency.

Max Bowen can be reached at mbowen@recorder.com or at 413-930-4074.