From the 1880s until after World War I, Texas prosecutions for adultery, fornication, rape, seduction, and sodomy were many, but formal penal code seemed much too merciful to suit most southerners, who believed in direct and personal redress of such wrongs. “Unwritten law” seemed to justify the killing—or at least maiming—of almost anyone who by actual physical contact or inappropriate comment offended southern notions of female virtue, male honor, or sanctity of marriage. Illicit sex is the catalyst in all the Texas murder trials recounted in Sex, Murder, and the Unwritten Law. In each account the victim, at least in the perception of the defendant, had committed some sexual impropriety. In every case the defendant opened fire with premeditated intent to kill. And in all the resulting trials, the defense relied at least in part on unwritten law. Bill Neal explores the imaginative machinations of defense lawyers who extricated obviously guilty clients when there appeared no legal basis upon which to peg a defense. Typically defense attorneys outmaneuvered prosecutors and judges, whose efforts to rein in excesses met with little success. These courtroom triumphs and underlying strategies are remarkable to lawyers, historians, and laypersons alike.