No one answered the door, despite the officers hearing people inside the house, according to NBC News. After 10 minutes, the officers obtained a key to the apartment from the landlord and allegedly found Gaines sitting on the floor pointing a long gun.The officers retreated and called for tactical support. The standoff lasted until 3 p.m., when, according to the police, Gaines allegedly said, "If you don't leave, I'm going to kill you."The police opened fired, wounding and killing her. The 5-year-old boy was wounded but is expected to survive, The Baltimore Sun reported "Perceiving not only her actions, but the words she used, we discharged one round at her; in turn, she fired several rounds back at us," police Chief Jim Johnson said during a news conference on Monday night, The Washington Post reported . "We fired again at her, striking and killing her. Tragically, in this circumstance, the child that was also in the dwelling was struck by a round."