She was a Brownie troop leader, a room mother, a Sunday school teacher and almost the definition of an Orange County soccer mom -- until she shot her two small daughters to death in 1991 while they slept in their home in Laguna Niguel, Calif. Kristine Cushing, then 39, said she was the victim of anti-depression medication, a debilitating heart condition and worry over the impending dissolution of her 17-year marriage to former Marine Corps fighter pilot John Cushing Jr. when she shot her daughters, ages 4 and 8, and then attempted to kill herself. She was found not...