"When the officers went in and made re-entry, they found him already deceased", Dean said, according to ABC 6.
Long's body was found inside an office adjacent to the bar's entrance. "We're proud of that", Fox said.
In that incident, deputies were called to his home, where Dean said Long was acting "irrationally".
"I already didn't wish it on anybody to begin with for the first time", Kelly said the Associated Press interview.
The marine corps told news organizations that Long served in Afghanistan between November 2010 and June 2011.
Long joined the Marines in 2008 and rose to the rank of corporal before leaving active service in 2013, Joseph Butterfield, a Marine spokesman, wrote in an email.
The extended magazine Long allegedly used can not be legally purchased in California under a 2000 law.
"Ron was a hardworking, dedicated sheriff's sergeant who was totally committed", Dean said of the man who was also his long-time friend and gym partner.
Here's what we know of Long so far.
Matt Wennerstron, a 20-year-old college student, said the shooter apparently had a 10-15 round magazine in his gun.
"It appears he walked up to the scene".
"I look up - the security guard is dead".
Kelly is a regular at the bar and was inside for around an hour when he heard the first shots.
Authorities in Southern California say a gunman killed 12 people late Wednesday during an attack at a bar and dance club.
President Donald Trump ordered the U.S. flag at the White House and other government buildings to be flown at half-staff following the shooting, which came just 10 days after a gunman killed 11 worshippers at a synagogue in Pittsburgh.
This undated photo provided by the Ventura County Sheriff's Department shows Sheriff's Sgt. Ron Helus, who was killed Wednesday, Nov. 7, 2018, in a deadly shooting at a country music bar in Thousand Oaks, Calif. Helus was taken to a hospital where he died on Thursday morning.
"I told his wife he died a hero", Dean said.
U.S. media said a number of the young people who were at the bar rampage in California on Wednesday night had survived that massacre.
"He went in there to save people and paid the ultimate price", he said. "I love you. I'll talk to you later'". Authorities said they visited that ranch-style house only once, in April, after a neighbor reported yelling and crashing sounds.
John was inside the bar near the front door with his stepdad.
President Trump tweeted on Thursday morning to say he been briefed on the shooting, describing it as "terrible", and praising the bravery of the police officers involved.
One officer said it had been "quite some time" since there was a shooting of any kind in Thousand Oaks. My parents let me go here.