A California jury will determine the mental competency of a former university student charged in the stabbing deaths of two people and attempted murder of a third. The attacks were violent and rocked the usually placid University of California, Davis, and the surrounding town. A Yolo County Superior Court judge said Tuesday that a medical expert determined Carlos Dominguez is not competent to stand trial. A jury will decide July 24. The 21-year-old defendant interrupted the hearing to say he wanted to apologize and that he was guilty. The stabbings rattled the community as businesses closed early and students were too scared to leave their homes even for daytime classes.