A 23-year-old man with a history of assaulting his girlfriend shot three generations of her family and killed her mother yesterday before shooting himself, police said.

According to police, the shooting began just after 11 a.m. inside an apartment on East 233rd Street in the Bronx, when a dispute between Sheldon Harris and his 24-year-old girlfriend, also the mother of his 2-year-old daughter, escalated into a violent assault.

Police said the man initially targeted only his girlfriend and shot her three times in the chest, but turned on her mother and grandmother when they rushed to help her. Police said he struck and killed his girlfriend’s mother, 53-year-old Joan Brown, with a bullet in her chest. He struck his girlfriend’s 74-year-old grandmother once in the torso.

All of the victims were brought to Jacobi Hospital, where the mother was pronounced dead, and the girlfriend and grandmother were in critical condition. Police said officers had been called to the home to resolve a domestic incident there at least once before. They also said the man had been arrested previously for assaulting his girlfriend.

Mr. Harris was charged with murder, two counts of attempted murder, and three counts of criminal use of a firearm.