Officer who shot, killed 18-year-old Half Moon Bay woman felt his life was in danger

The incident took place at about 9:20 p.m. at the Moonridge housing complex on Miramontes Point Road.

Trieu has been in law enforcement for nine years, and has been with the San Mateo County Sheriff’s Office for several years, Rosenblatt said.

According to Rosenblatt, the last officer-involved shooting in the San Mateo County Sheriff’s Office was in 2013, and in that case, the person shot was not killed. The last time an officer-involved shooting ended with the death of a suspect was in 2008, according to Rosenblatt.

“Those statistics speak for themselves, but it’s unfortunate that once in a while deputies are forced to use their weapons, and this was one of those cases,” Rosenblatt said.

The information received by emergency personnel who responded to the incident was that the woman was acting erratically and violently and had a knife. The woman’s family asked her to put the knife down, and when she didn’t comply, family members called the fire department for medical assistance, Rosenblatt said.

Rosenblatt explained that in a situation where a person may be a danger to emergency personnel, sheriff’s deputies are the first to respond to make sure the scene is safe for medical and fire crews.

The fire department was staging nearby while deputies secured the scene.

Rosenblatt said that within about 20 seconds of arriving on the scene, the shooting occurred.

Trieu is on paid administrative leave while the incident is investigated, Rosenblatt said.

No deputies were injured in the incident.

A joint investigation by the San Mateo County Sheriff’s Office and the San Mateo County District Attorney’s Office is underway.