A police officer is among the dozen people killed in a mass shooting Wednesday night at a Thousand Oaks, California, bar hosting a country music night.

Ventura Country Sheriff Geoff Dean gave a news conference early Thursday morning in which he tearfully announced the death of Sheriff’s Sgt. Ron Helus, a 29-year veteran of the police force who was among the first responders to the scene at Borderline Bar and Grill.

“I told his wife he died a hero — he went in to save lives,” Sheriff Dean told reporters, according to CBS News.

The sheriff said that Sgt. Helus was planning to retire in the next year or so.

“Ron was a hardworking, dedicated sheriff’s sergeant,” Dean said. “He was totally committed and he gave his all.”

Sheriff Dean also said the gunman, who has not been identified, was found dead inside the venue after more officers entered the building. He said authorities believe it is possible the gunman took his own life but that police have not determined how the gunman was killed. Including the suspect, the death toll is now at 13 people.

Though witnesses reportedly said the weapon the gunman used sounded like it could have been a semi-automatic firearm, the sheriff said at the news conference that investigators have so far only discovered a handgun at the scene.

Additional victims have not yet been identified. CrimeOnline will provide further updates when more information is available.

[Feature image: Ventura County Police]