In March 2008, retired teacher Charles Johnson opened fire at a hospital in Georgia, killing three employees; police said he sought revenge against staffers who cared for his mother before she died in 2004. Last April, Mario Ramirez, a pharmacy technician at California's Long Beach Memorial Medical Center, shot and killed two supervisors before committing suicide; his motive may never be known. Last December, Robert Yagi, driven by love and compassion, shot his terminally ill wife as she lay in her hospital bed in Hawaii; she survived, but he later committed suicide. On March 2, Stanley Lupienski, an elderly patient...