Firefighters salute from an overpass as a motorcade with the body of Ventura County Sheriff's Sgt. Ron Helus goes by Thursday, Nov. 8, 2018, in Newbury Park, Calif. Helus was fatally shot while responding to a mass shooting at a country music bar in Southern California.

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.

People cry as a law enforcement motorcade escorts the body of Ventura County Sheriff's Department Sgt. Ron Helus from the Los Robles Regional Medical Center Thursday, Nov. 8, 2018, in Thousand Oaks, Calif., after a gunman opened fire Wednesday evening inside a country music bar, killing multiple people including Helus.

An honor guard salutes the body of Ventura County Sheriff's Department Sgt. Ron Helus before it departs the Los Robles Regional Medical Center Thursday, Nov. 8, 2018, in Thousand Oaks, Calif. Helus was killed after a gunman opened fire the night before inside a country dance bar crowded with hundreds of people on "college night."

Potential witnesses sit near the shooting scene on Thursday, morning.

An FBI agent talks to a potential witness in Thousand Oaks, Calif. where a gunman opened fire Wednesday inside a country dance bar crowded with hundreds of people.

A victim is carried from the scene of the shooting, Wednesday evening, in Thousand Oaks, Calif.

People comfort each other near the scene of the mass shooting in a Thousand Oaks, Calif. bar Wednesday night.

A victim is treated near the scene of the shooting at the Borderline Bar & Grill.

People comfort each other as they stand near the Borderline Bar & Grill in Thousand Oaks, Calif., where a gunman opened fire Wednesday.

A victim is treated near the scene of a shooting in Thousand Oaks, Calif. late Wednesday.

Police vehicles line a road in the vicinity of the shooting in Thousand Oaks, California, early Thursday.

A forensics team gets ready work the scene of the shooting early Thursday morning in Thousand Oaks, Calif.

Police move through the vicinity of the Borderline Bar & Grill early Thursday.

Police vehicles block an intersection in the vicinity of the mass shooting in Thousand Oaks, California, early Thursday morning.

Grieving people are led into the Thousand Oaks Teen Center where families have gathered after a deadly shooting at a bar in Thousand Oaks, California.

Family members are led into the Thousand Oaks Teen Center where families have gathered after a deadly shooting at a bar on Thursday, Nov. 8,2018, in Thousand Oaks, Calif.

People cry as a law enforcement motorcade escorts the body of Ventura County Sheriff's Department Sgt. Ron Helus from the Los Robles Regional Medical Center Thursday, Nov. 8, 2018, in Thousand Oaks, Calif., after a gunman opened fire Wednesday evening inside a country music bar, killing multiple people including Helus.