Johnny Paul Penry was born on May 5, 1956, in Texas. He grew up in an abusive household, where he suffered severe physical abuse that reportedly led to lifelong intellectual disabilities. His IQ was estimated between 51 and 63, classifying him as intellectually disabled. His mother allegedly beat him, locked him in closets, and denied him basic education, leaving him with minimal reading and writing skills.

Penry had a history of violent behavior and criminal activity before the murder that would later define his life. At the time of the crime, he was on parole for a 1977 rape conviction. Despite his intellectual disabilities, he was considered legally competent to stand trial and was released on parole in early 1979.

On October 25, 1979—just three months after his release from prison—Johnny Paul Penry broke into the home of 22-year-old Pamela Moseley Carpenter in Livingston, Texas. Carpenter, the younger sister of NFL kicker Mark Moseley, had met Penry weeks earlier when he delivered an appliance to her home as part of his job. That fateful day, Carpenter was working on a Halloween costume for her niece using a pair of scissors. Penry used those same scissors to stab her, then proceeded to rape and bludgeon her before leaving her for dead. Despite her severe injuries, Carpenter managed to call a friend and provide a brief description of her attacker while being transported to the hospital. She later succumbed to internal injuries, but her call played a crucial role in identifying Penry as the perpetrator. He was arrested later the same day, still within the vicinity.

Penry was sentenced to death on April 9, 1980. However, the legal saga surrounding his case would stretch for nearly three decades and reach the highest court in the United States on multiple occasions. In 1989, the U.S. Supreme Court ruled in Penry v. Lynaugh that the Eighth Amendment did not categorically prohibit the execution of individuals with intellectual disabilities, though it acknowledged the inadequacies in Texas's jury instructions regarding the consideration of mental impairment. His sentence was overturned, but not the conviction.

He was retried in 1990 and again sentenced to death, only to have that sentence challenged and brought before the Supreme Court again in Penry v. Johnson (2001). The Court ruled that the jury had again received constitutionally inadequate instructions about weighing Penry’s intellectual disability as a mitigating factor. In 2005, the Texas Court of Criminal Appeals once again overturned his death sentence, citing the same recurring issue. By 2006, the U.S. Supreme Court declined to reinstate the sentence, effectively ending the state’s efforts to execute him.

In 2008, after nearly 30 years of litigation, a plea agreement was reached: Johnny Paul Penry would no longer face the death penalty but would instead serve three consecutive life sentences without the possibility of parole.