OCALA, FL—In the latest act of youth violence to shock the nation, 14-year-old home-schooler Jeffrey Kunz opened fire on the family breakfast nook Monday, killing three and injuring two. "We were just about to start Jeffrey's algebra lesson when I heard several loud pops," said Iris Kunz, 44, the assailant's mother/teacher and one of the injured. "But then I saw blood on Jeffrey's sister Melissa and realized someone was shooting." The gun-wielding teen, who was eventually subdued by SWAT-team agents, was said to be angry at his mother over a science grade.