LONG BEACH, Calif. (AP) — The fatal shooting of an 18-year-old woman by a Southern California school safety officer last month is being investigated as a possible homicide, police said Thursday.

Manuela “Mona” Rodriguez, who had been declared brain dead after the Sept. 27 shooting, died Tuesday after she was removed from life support, her family said.

Because of her death, “Detectives are now investigating this matter as a homicide,” the Long Beach Police Department said in a statement.

The officer who shot her has been fired by the Long Beach Unified School District, it was announced Wednesday.

Eddie F. Gonzalez was dismissed by unanimous vote of the district board because he violated district policy, Superintendent Jill Baker said. Gonzalez has not publicly commented and the Teachers Association of Long Beach, which represents many of the school district’s employees, did not immediately respond to an email seeking comment or information about how to contact Gonzalez or whether he has a lawyer who could speak on his behalf.

Rodriguez, the mother of a 5-month-old son, was shot in the back of the head in a parking lot near Millikan High School in Long Beach. She was sitting in the passenger seat of a car that was driving away after Rodriguez had gotten into a fight with a 15-year-old girl, police have said.

Video posted online appeared to show the safety officer firing at least two shots as the car moved off next to him. At least one bullet pierced a window of the car.