Law enforcement officials said Wednesday that a deputy in San Mateo County shot and killed an 18-year-old woman who was wielding a knife.
The incident began around 9:20 p.m Tuesday when deputies responded a medical call at a housing complex in Half Moon Bay, authorities said.
The call quickly escalated into a law enforcement matter when family members told a dispatcher that a female relative was "displaying erratic and violent behavior," according to the San Mateo County Sheriff's Office.
Officials said that family members told the dispatcher that the woman had a knife.
"The first deputy arrived on scene and was immediately confronted by the knife-wielding woman in such a manner that he feared for his life and the safety of those around him," the Sheriff's Office said.
The deputy opened fire and struck the woman at least once, officials said. She was declared dead at the scene.
The incident was under investigation by the Sheriff's Office and the San Mateo County district attorney's office.