The Cook County Sheriff’s Office is not liable for the actions of a correctional officer who broke into her ex-girlfriend’s home and shot two people before taking her own life, a federal judge held.In a written opinion Monday, U.S. District Judge Jorge L. Alonso granted summary judgment in favor of Sheriff Thomas J. Dart and the current and former supervisors in the sheriff’s office named as defendants in a lawsuit filed by members of the Jaimes family. Alonso also granted summary judgment in favor of the Cook County …