FILE - In this Sunday, Nov. 11, 2018, file photo, former high school track coach Evie Cluke talks about her interactions with Ian David Long, who authorities say shot and killed 12 people at a Southern California bar in Thousand Oaks during an interview near her home in Montclair, Calif. Cluke says former student Long was volatile and sadistic and once told her he wanted to join the military so he could kill people for his country. Cluke coached Long at Newbury Park High School in Newbury Park, Calif., in 2008 and 2009. (AP Photo/Amanda Lee Myers, File)
FILE - In this early Thursday, Nov. 8, 2018, file photo, people comfort each other as they stand near the scene in Thousand Oaks, Calif., where a gunman opened fire inside a country dance bar crowded with hundreds of people. If authorities have concluded why Ian David Long shot and killed 12 people at the Southern California bar, they aren't sharing. His family isn't talking, either. That has left a community still in mourning to wonder why, but also ask who was the man who shattered the sense of security in the Los Angeles suburb of Thousand Oaks? (AP Photo/Mark J. Terrill, File)
THOUSAND OAKS, Calif. — At first, the outlines of the mass shooter’s 28 years appeared unremarkable.