Actress Vanessa Marquez has been shot and killed by police in Los Angeles after they were reportedly called to make a welfare check on her.
Lt Joe Mendoza told the South Pasadenan that police had been called about a woman suffering from seizures.
He said as police started talking to the former ER regular, 49, she pulled out what he says looked like a real gun at which point she was shot at least once in the torso by an officer.
"At the time [of the shooting] there was an LA County mental health clinician here with the officers," Lt Mendoza said. "They began to communicate with her, she became very uncooperative and during that contact she armed herself with a handgun, she pointed it at the officers and an officer-involved shooting occurred."
She was rushed to hospital and pronounced dead there.
Lt Mendoza said Marquez, who played nurse Wendy Goldman on ER from 1994-1997, appeared to be "gravely disabled" when officers first made contact with her.
Marquez had spoken on social media about her mental health struggles and her Twitter says she had terminal celiac disease.
Last year, Marquez made headlines when she accused ER co-star George Clooney of having her black-listed in Hollywood for speaking out about alleged harassment on the set of the medical drama.
Clooney was forced to release a statement denying he had any involvement in Marquez's waning career.
"I had nothing to do with casting," he said. "I was an actor and only an actor. If she was told I was involved in any decision about her career then she was lied to. The fact that I couldn't affect her career is only surpassed by the fact that I wouldn't."
Marquez had also starred in episodes of Melrose Place and Seinfeld.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• The Word
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.