Dennis McCarthy, 52, was one of six people killed during the Long Island Rail Road shooting on the 5:33 p.m. train from Penn Station on December 7, 1993. The train stopped at Jamaica, then continued east; as it neared Merillon Avenue station in Garden City Park, a passenger stood up and began firing with a 9mm semi-automatic pistol. The shooter moved down the aisle of the third car, firing at close range and creating scenes of people hiding under seats and pushing for doors until other passengers charged him and subdued him while an off-duty LIRR officer at the station placed him in handcuffs at the scene.

The attacker, identified as Colin Ferguson, was tried in court after the massacre. He dismissed lawyers and insisted on representing himself, at one point questioning victims. He offered shifting explanations, including a claim he had been asleep and an assertion that an unidentified white passenger was responsible; those defenses were rejected. In February 1995 Ferguson was convicted of murdering six passengers, attempting to murder others, and related weapons charges, and received a sentence intended to keep him confined indefinitely.