On the afternoon of September 8, 1933, a mass shooting took place in Belfast, Maine. Adrian F. Jones, 66, armed himself with a shotgun, a .38-caliber Winchester rifle, 500 rounds of ammunition, and two automatic revolvers before leaving his house at about noon wearing an overcoat that concealed the pistols.
Jones arrived at the corner of High and Main streets shortly before 1 p.m. and walked up behind 65-year-old Herbert E. Ellis, firing eight buckshots into his back; two pierced his chest, and Ellis died at the scene in a pool of blood. Jones then proceeded to Washington Street, where, from about 50 feet away, he fired on three men standing in front of the Blazo Trucking Company office: 73-year-old William W. Blazo, the company's owner; his 37-year-old son Raymond Blazo; and 57-year-old veterinarian Reginald B. Stanhope, whose office was above Blazo's. Raymond Blazo died almost instantly from two chest wounds. William Blazo was mortally wounded in the arm, chest, and abdomen. Stanhope was shot in the neck, a lung, and a kidney, and died about two hours later. A fourth man in the doorway of the office escaped unharmed.
Jones then fired at a man sitting on a wagon; the man was unhurt, but the shot struck one of his horses. Jones subsequently crossed the street into the Tyler Blacksmith shop and barricaded himself inside. Police officers and armed volunteers surrounded the building. A few minutes later, Jones shot himself in the head with one of his revolvers and died.
Jones harbored longstanding grudges against two of the victims. His grievance against Ellis reportedly dated back as much as 20 years, to a period when the two had been neighbors. Jones had also expressed a wish to "eradicate" Blazo's trucking company, though the specific reason was not recorded. Those grudges, combined with what the source describes as his mental instability, were considered the likeliest motive for the attack.
Jones was described as having been considered harmless prior to the shooting because he had never threatened anyone, despite being known locally for frequently carrying firearms and being a skilled hunter. His landlady said that the night before the shooting he had been restless and talked incoherently to himself, which she considered typical for him, though he was noted to be more irritable than usual the following morning. Jones had worked as a farmhand in Belfast before working at psychiatric institutions in Cranston, Rhode Island, and Northampton, Massachusetts, later returning to Belfast. He had never married and had no living immediate relatives.