There were six off-duty officers from various agencies inside the Borderline Bar & Grill at the time of the shooting, Ventura County Sheriff Geoff Dean said.
Dean said a mother recalled that the officers stood in front of her daughter to protect her.
The suspected gunman Ian David Long was on active duty with the US Marine Corps from August 2008 to March 2013, according to Department of Defense records.
At a news conference, Ventura County Sheriff Geoff Dean said Long, 28, used a Glock .45-caliber handgun during last night's shooting at the Borderline Bar & Grill in Thousand Oaks, California.
The suspected gunman, Ian David Long, shot himself, Ventura County Sheriff Geoff Dean said at a news conference Thursday.
He was dead when officers made entry into the bar.
The suspected gunman in last night's deadly shooting has been identified as 28-year-old Ian David Long, according to Ventura County Sheriff Geoff Dean.
Long, a US Marine Corps veteran, used a Glock .45-caliber handgun during the shooting, the sheriff said.
Authorities had "minor" run-ins with Long in the past, Dean said. Here's how he described them:
"We've had several contacts with Mr. Long over the years, minor events, a traffic collision. He was a victim of a battery at a local bar in 2015. In April of this year, deputies were called to his house for a subject disturbing. They went to the house, they talked to him. He was somewhat irate. Acting a little irrationally. They called out our crisis intervention team, our mental health specialists who met with him, talked to him and cleared him. Didn't feel he was qualified to be taken under 5150. And he was left at that scene last April," the sheriff said.
Twenty-one people hurt in last night's bar shooting were treated and released from area hospitals, according to the Ventura County Sheriff's Office.
Details on the victims' injuries were not released.
California Lutheran University in Thousand Oaks, California, has canceled classes today because of a shooting at Borderline Bar & Grill, according to their website.
An alert on the university's website reads:
“Classes will not be held today, Nov. 8. Borderline hotline number: 805-465-6650. The university community is invited to gather at the chapel, which is open.”
Authorities believe they have identified the suspect in the Thousand Oaks, California, shooting, according to a law enforcement source.
The source cautions information is early: But the suspect is believed to be 29 years old.
Multiple Pepperdine University students were at the Borderline Bar & Grill in Thousand Oaks during the shooting, the university said in a statement.
Pepperdine will hold classes today as scheduled and encouraged students who need to adjust their schedules because of the shooting to do so.
"University officials have been working on site with law enforcement to confirm their safety and well-being, and our prayers and condolences are with everyone impacted by this senseless act of violence," Pepperdine said in the statement.
A procession for slain deputy Sgt. Ron Helus is being planned for 1 p.m. ET, Capt. Garo Kuredjian, spokesperson of Ventura County Sheriff’s Office, tells CNN affiliate KCAL/KCBS.
The procession will start at Los Robles Hospital and end at the Ventura County Medical Examiner’s Office.
Sgt. Helus was killed after entering the Borderline Bar & Grill during last night's shooting. Helus died at a hospital, police said.
"He went into save lives, to save other people." Ventura County Sheriff Geoff Dean said of Helus, his voice breaking at a news conference early Thursday.