In December of 1987, Ronald Gene Simmons snapped and killed 14 members of his family, from his wife to his children to their spouses to his own grandchildren, as well as an acquaintance and a stranger and wounded two others. Once police caught up to him, he was taken into custody without incident, and went to trial.
Sources for this episode:
Wikipedia - Chicago, Dover, Arkansas, Ronald Gene Simmons, Tucker Unit, Cummins Unit