THOUSAND OAKS, the United States, Nov. 8 (Xinhua) -- Local authorities identified 28-year-old Ian David Long as the gunman of a mass shooting Wednesday night in the city of Thousand Oaks in Southern California, which has left 13 people dead including an officer and the gunman.

A total of 25 people were injured in the shooting, according to local authorities.

Ventura County Sheriff Geoff Dean said the gunman was Ian David Long, 28, a Marine Corps veteran, who was described as "acting a little irrationally" when police were called to his home earlier this year to investigate a disturbance. He lived in Newbury Park, near Thousand Oaks.

Dean said the gunman was armed with a Glock 21-a brand of .45-caliber handgun.

"The weapon was designed in California to hold a magazine of 10 rounds and one in the chamber, but he had an extended magazine on it," Dean said.

Sheriff's officials said the shooter fatally shot himself after the massacre. He was found inside an office near the entrance of the venue.

In the neighborhood where Long lived, residents said they were well aware of his problems.

Richard Berge, 77, was quoted by local media as saying the former Marine had PTSD (post-traumatic stress disorder) and was known to kick in the walls of the home. Long lived with his mother, Berge said.

A total of 25 other people were injured in the shooting, including 23 who self-transported themselves to hospitals, and two who were taken by ambulance, according to the Ventura County Fire Department.

A procession was held Thursday morning for Deputy Sgt. Ron Helus killed while responding to the mass shooting.

Helus' body was transported via motorcade from Los Robles Hospital to the Ventura County Medical Examiner's Office. People stood along the route with grief, paying salute to the officer.

Helus was a 29-year veteran who was set to retire next year. He is survived by his wife and son.

Ralph Chapman, whose son is a colleague of Helus, told Xinhua his son was among the officers running into the bar to respond to the shooting.

Chapman said he was very sad and worried when he heard that one officer was killed at the site, very afraid that it might be his own son.

Chapman's son was a member of the motorcade transporting Helus' body on Thursday morning.

Chapman said he used to serve at U.S. troops in Vietnam for two years, and he believed PTSD should not account for the mass shooting.

Tami Teece, who was a survivor of the mass shooting in Las Vegas last year, which killed 59 people and wounded more than 500, was among the crowd mourning the death of Helarus along the road.

She, who also has PTSD, told Xinhua the government should spend more money to set up mental hospitals for veterans to address their psychological problems.

The motive of the shooter remains unknown.

Authorities said hundreds of people were inside the bar when the gunfire rang out.

No other victims have been identified by officials.

A family assistance center has been set up at 1375 E. Janss Road in Thousand Oaks.