Diane Martinez Marin, a seven-year police dispatcher, had never taken a call of such magnitude on Saturday in Pasadena.
The man on the other line said he had just killed someone.
"Mainly, I was concerned that this person still had weapons," Marin said. "I was concerned what they were planning to do to themselves and to the officers."
She could be heard in a 911 recording telling the suspect in a triple-homicide that no one wanted to see him harmed as she tried to help end a violent standoff at a Pasadena home.
John Izeal Smith, 44, is suspected of killing a woman Saturday inside a house, then killing two men outside and firing at officers before holing up back inside the house. Officers who responded came under heavy gunfire as they approached one of the victims outside, police said.
On Monday, authorities released 911 audio recordings of Smith's 25-minute call to a dispatcher who assisted a crisis negotiator in bringing the situation to an end without more casualties. Marin said Smith told her that he "killed someone," then continued speaking with her as officers took up positions outside the house.
- Updates: NBCLA News App
"It sounded like he wanted to talk to someone, and he was expressing to me things that had nothing to do with the crime itself," Marin said. "My main concern was the safety of the officers and anyone out on the street. I was concerned that this person still had weapons. I was concerned about what they were planning to do to themselves and to the officers."
Officers later determined Smith had three firearms and 90 rounds of ammunition in the home in the the 1700 block of Summit Avenue, according to Pasadena police. The weapons -- two high-powered assault-style rifles and a semi-automatic pistol -- appear to have been purchased legally, police added.
No officers were injured in a standoff that ended without a single round being fired by law enforcement agents. Several officers took cover behind police vehicles, including a sport utility vehicle pierced by eight rounds.
Smith surrendered Saturday evening and remained in jail Monday on $1 million bond.
"The suspect willfully murdered and injured innocent people without warning as he fired more than 40 rounds from a semi-automatic rifle," Pasadena Police Chief Phillip Sanchez said in a statement Sunday. "However, the courage of our dispatchers, police officers, firefighters and community members who valiantly tried to help the victims is impressive and speaks to the resolve of our community."
Authorities are attempting to confirm whether a landlord dispute was behind the violence. There was a "long-term" relationship between the gunman and the people in the home, police said Monday.
The woman killed in the house was identified as 59-year-old Maria Teresa Aguiar. The two men were identified as Luis Aguiar, 90, and Jose Uribe, 30. It was not immediately clear whether the Aguiars are related.
Two others suffered minor to moderate injuries.