THOUSAND OAKS, Calif.—Authorities trying to make sense of why a gunman killed 12 people at a Southern California bar are not publicly discussing what they’ve learned, but at least one Instagram post he made after beginning the massacre has emerged as an early focus.
Social media platforms have scrubbed that and any other posts following Wednesday night’s massacre. But one law enforcement official said Ian David Long, a 28-year-old former Marine, posted about his mental state and whether people would believe he was sane.
