SAN JUAN, Puerto Rico (AP) — Authorities in Puerto Rico have arrested the stepdaughter of a woman killed last month in a drive-by shooting while in her car with her two biological daughters.

Police said Wednesday that 29-year-old Keishla Pérez was charged with first-degree murder and two counts of attempted murder. Two other men have already been charged in the case.

It was not immediately clear if Pérez had an attorney.

Hilda Padilla was shot in the head on Sept. 30 in the capital of San Juan. Her daughters, ages 8 and 17, were not injured.

Police have not yet provided a motive.