LOS ANGELES (AP) — Police said they were trying to determine what prompted a man to shoot his grandmother and wound another woman before he crashed his car and ran into a busy supermarket, where he held dozens of people hostage in a tense standoff with scores of heavily armed officers outside.A woman was shot and killed when the gunman ran into the Trader Joe's supermarket in Los Angeles' Silver Lake section on Saturday, but no hostages were seriously hurt before the man [...]