Investigators said two men were involved in a dispute, which escalated into a physical altercation.
Police said the victim, 43-year-old Vicky Griffin, attempted to break up the fight.
She suffered a stab wound to the chest. Griffin was taken to Brookdale Hospital where she was pronounced dead.
Police have arrested 30-year-old Abdul Mattocks of Washington Avenue in Brooklyn.
Mattocks faces charges of murder in the second degree and manslaughter.
NEW YORK AND TRI-STATE AREA NEWS