Investigators said Tuesday they still don't know why 28-year-old Ian David Long attacked staff and customers at the Borderline Bar and Grill in the Los Angeles suburb of Thousand Oaks on Nov. 7.

The gunman who killed 12 people at the Borderline Bar & Grill in Thousand Oaks, California, was a 28-year-old veteran of the Marine Corps who had previous run-ins with the law, officials said.

Ian David Long's behavior alarmed many but never became threatening enough for him to be taken into custody for mental health treatment. Those who knew the Afghanistan war veteran described him as ...

Undated photo of Ian David Long, the suspect the mass shooting at a bar in Thousand Oaks, California, during his time in the U.S. Marine Corps is seen on the Facebook page of his mother, Colleen Long.

Marine Corps veteran Ian David Long, 28, the man accused of killing 12 at a nearby country bar late Wednesday before shooting himself, was a former machine gunner and decorated combat veteran of ...

Police identified 28-year-old Ian David Long as the suspect in the shooting at a Thousand Oaks, Calif., bar that left at least 13 dead, including the suspected gunman.

High school coach says bar shooting suspect assaulted her 01:14. NEWBURY PARK, Calif. -- A former track coach at Newbury Park High School in California says Ian David Long, the 28-year-old suspect ...

THOUSAND OAKS, Calif. — Neighbors of Ian David Long described the man who shot and killed 12 people at a country music bar as distant in public but combative with his mother inside the suburban ...

Ian David Long is seen in an image taken from Facebook. Long, 28, was a former military machine gunner who apparently killed himself after the Wednesday night attack in Thousand Oaks, the quiet ...

Ian David Long was a gifted sprinter whose fast-twitch muscles propelled him around the Newbury Park High School track. But one day during his senior year, each time he passed the girls’ head ...

MONTCLAIR, Calif. (AP) — A second high school coach of the gunman who killed 12 people at a Southern California bar recalled him on Sunday as volatile and intimidating, and said that repeated ...

THOUSAND OAKS, Calif. -- Ian David Long, 28, has been identified as the suspected gunman in the mass shooting at a Thousand Oaks nightclub.