'ER' Actress Vanessa Marquez Shot and Killed By L.A. Authorities

Police responded to her residence on a welfare check before the shooting took place.

Actress Vanessa Marquez was shot and killed by South Pasadena police on Thursday after officers responded to her residence on an emergency medical call, the Los Angeles County Sheriff's Department confirmed to The Hollywood Reporter. Detectives from the sheriff's office are assisting in the investigation.

The incident occurred around 1:48 p.m. in the 1100 block on Fremont Avenue, according to authorities.

Officers from the Pasadena Police Department responded around noon to the 49-year-old Stand and Deliver actress' home to conduct a welfare check. When officers arrived on scene, Marquez was having seizures and a request for additional medical personnel was sent, according to authorities.

At some point, while speakingto Marquez, authorities say she became uncooperative and appeared to be possibly suffering from mental health issues. A Los Angeles County Mental Health clinician was also sent to the scene.

Police and the clinician spoke to Marquez for about 90 minutes, at which time she allegedly retrieved a gun and pointed it at the officers. She was shot and killed. Authorities say it was later discovered the firearm was a BB gun.

Marquez was transported to a local hospital where she was pronounced dead.

The actress was also known for playing nurse Wendy Goldman on the first three seasons of ER, NBC's long-running medical drama.

In October of last year, Marquez, via a series of posts on Twitter, accused star George Clooney of helping to get her "blacklisted" after she spoke out