In 1967, Kenneth Allen McDuff was sentenced to death and put on death row for the brutal murder of three high school students, when he was only 19. Twenty years later, in Waco, Texas, U.S. Marshal Parnell McNamara is investigating the mysterious abduction and murder of Melissa Northrup, a convenient store clerk, when he discovers a 1985 tan Thunderbird near the crime scene registered to a Kenneth Allen McDuff. How does a death row inmate become the prime suspect of a brutal murder 20 years later?