"Taking the life of an innocent person is a police officer's greatest nightmare," Interim L.A. County Sheriff John Scott said during a news conference.
Authorities responded to an assault with a deadly weapon call in the 900 block of Palm Avenue at 9:29 p.m. Monday. At the time, their information stated that the suspect was a white male wearing a black shirt.
When deputies arrived at the scene, they saw a man coming out of an apartment covered in blood, and then a second man ran out. That man, identified as 30-year-old John Winkler of West Hollywood, was wearing a black shirt and appeared to be lunging at the victim, investigators said.
"Believing Winkler was the assailant and the assault was ongoing ... three deputies fired their duty weapons at him," the sheriff's department said in a statement.
Both Winkler and the other victim were struck by gunfire.
Inside the apartment, deputies found two other men fighting, and one of the men, identified as 27-year-old Alexander McDonald, was choking the other man. Deputies were able to stop the fight, and McDonald was taken into custody without further incident.
Upon further investigation, detectives learned that McDonald was the one who held Winkler and two other men at knifepoint inside the apartment. McDonald was a resident at the apartment, and one of the victims was his roomate, while Winkler and the other victim were just visiting.
"In a rage, the suspect began stabbing the men and fighting with them as the deputies arrived," the sheriff's department said in a statement.
All four men were taken to a local hospital, where Winkler died from a single gunshot wound. The victim who had initially rushed out covered in blood was treated for stab wounds to the neck and a gunshot wound to the leg. Police say he is in stable condition.
The third victim was treated for stab wounds to the legs, arms and chest and has since been released from the hospital.
McDonald was treated for minor injuries. He has been charged with one count of murder, two counts of attempted murder and one count of torture. His bail was set at $4 million.