12 killed in US bar shooting
Former marine took his own life after gun rampage in California
Twelve people including a sheriff's sergeant were killed in a mass shooting inside a crowded southern California bar by a gunman who is then believed to have taken his own life.
The killer was identified as Ian David Long, a 28-year-old former US marine with mental health issues, with investigators trying to find the motive for the attack at a venue hosting a country music evening for students.
The hooded killer used a smoke bomb and a handgun, sending hundreds of people fleeing in terror.
Ventura County Sheriff Geoff Dean said his department had several previous contacts with Long, including a call to his home in April, when deputies found him angry and acting irrationally.
The sheriff said a mental health crisis team was called at the time and concluded Long did not need to be taken into custody.
Patrons at the bar screamed in fear, shouted "Get down!" and used bar stools to smash second-floor windows and jump to safety as gunfire erupted at the Borderline Bar & Grill, a Thousand Oaks venue popular with students from nearby California Lutheran University.
The dead included 11 people inside the bar and a sheriff's sergeant who was the first officer inside the door, the sheriff said.
"It's a horrific scene in there," Mr Dean said in a press conference at a car park.
"There's blood everywhere."
The killer deployed a smoke device and used a .45-calibre handgun.
It was the deadliest mass shooting in the US since 17 students and teachers were killed at a Parkland, Florida, high school nine months ago.
It also came less than two weeks after a gunman massacred 11 people at a synagogue in Pittsburgh.
That, in turn, closely followed the series of pipe bombs mailed to critics of President Donald Trump.
Mr Trump praised police for their "great bravery" in the California attack and said: "God bless all of the victims and families of the victims."
The gunman was tall and wearing all black with a hood and his face partly covered, witnesses told TV stations.
He first fired on a person working the door, then appeared to shoot at random at people inside, they said.
"I dropped to the floor," Sarah Rose DeSon told ABC's 'Good Morning America'.
"A friend yelled, 'Everybody down!' We were hiding behind tables trying to keep ourselves covered."
Sheriff's Sergeant Ron Helus and a passing highway patrolman arrived at the Borderline around 11.20pm in response to several 911 calls, heard gunfire and went inside, the sheriff said.
Sgt Helus was immediately hit with multiple gunshots, Mr Dean said.
The highway patrolman pulled Sgt Helus out, then waited as a Swat team and scores more officers arrived.
Sgt Helus died early yesterday at a hospital.
By the time they entered the bar again, the gunfire had stopped, according to the sheriff.
They found 12 people dead inside, including the gunman who apparently took his own life, the sheriff said.
"There's no doubt that they saved lives by going in there and engaging with the suspect," said Mr Dean, who was set to retire today.
He praised the murdered officer, a close friend, as a hero, saying: "He went in there to save people and paid the ultimate price."
The body of the slain sheriff's officer was taken by motorcade from the hospital to the coroner's office yesterday. Thousands of people stood along the route. Firefighters used two ladder trucks to raise a giant American flag over the route.
Helus was a 29-year veteran of the force with a wife and son and planned to retire next year.