Wearing his uniform and sitting in his Palm Beach Sheriff’s-issued car, a deputy waited for his ex-girlfriend. When he found her walking her dog, he stepped out of his car and shot her before shooting and killing himself.The shooter, Michael DeMarco, 55, had been with the sheriff’s office since 1995, according to Palm Beach Sheriff’s Office spokeswoman Teri Barbera. His relationship with the woman, a bank worker, began in May and ended three weeks before the shooting. The woman shot was taken to Delray Trauma Center and in critical but stable condition.