LOS ANGELES (AP) -- The panicky 911 caller said a man with a 10-inch butcher knife was threatening people. So when Los Angeles County sheriff's deputies saw a wounded, bloody man rush out of a West Hollywood apartment with someone on his heels, they opened fire.
But the man they gunned down Monday night wasn't a mad slasher; he was a fleeing hostage.
John Winkler, 30, an aspiring television producer, died at a hospital.
"Taking the life of an innocent person is a police officer's greatest nightmare," Interim Los Angeles County Sheriff John Scott said Thursday at a news conference.
The entire department mourned Winkler's death, he added.
Winkler was "hanging out" with some friends who lived in the apartment below him on Palm Avenue when a man who also lived in that apartment, Alexander McDonald, climbed over the balcony with the knife, sheriff's homicide Lt. David Coleman said.
McDonald was "in an incoherent state of mind, seemed very paranoid, which was uncharacteristic," Coleman said.
McDonald took his roommate, Winkler and another man hostage, then flew into a rage and began stabbing and fighting with them, authorities said.
"We don't know what caused his rage or what caused his outburst," and it was unclear whether drugs were involved, Coleman said.
Someone called 911 and arriving deputies were told the hostage-taker was a thin man in a black shirt.
Deputies announced themselves and pounded on the door and at that moment one of the stabbing victims took the opportunity to escape, Coleman said.
"The door suddenly opened and a man with blood spurting from his neck entered the doorway" with Winkler -- a thin man wearing a black shirt -- running after him only inches away, Scott said.
The fleeing man appeared to be under "continuous attack," the sheriff said.
Three deputies fired four shots, and a bullet mortally wounded Winkler. The other man was hit in the leg and was hospitalized in stable condition, according to a sheriff's department statement.
From the open apartment door, deputies heard fighting and burst inside, where they allegedly saw McDonald choking and tearing at the face of a man on the floor.
That man was treated for stab wounds and other injuries and released, according to the statement, which said a large knife was found in the apartment.
McDonald, 27, was treated for minor injuries. County prosecutors have charged him with torture, murder and two counts of attempted murder. He remained jailed Thursday.
McDonald was involved in information technology or computer programming and had no criminal history, Coleman said.
There was nothing in his past behavior that was consistent with the attack, he said.
Winkler had moved to West Hollywood from Washington state six months ago to work in the entertainment industry, his friend, Devin Richardson, told the Los Angeles Times.
Winkler's Facebook page said he studied directing at the Seattle Film Institute and was in the class of 2010.
Institute communications director Chris Blanchett told The Seattle Times that Winkler was a good student and "a genuinely nice guy."
Another friend, Trevor Jess, told KING-TV in Seattle that Winkler was "just starting out, ready to climb the ladder and that's the thing that breaks my heart."
The deputies, all department veterans, were removed from patrol after the shooting but were expected to return to full duty next week, sheriff's officials said.