Jeffrey Dillingham was born on March 6, 1973, and grew up in Texas. He held a modest job as a clerk in a video rental store. At the time of the crime, he was only 19 years old. He was described by people who knew him as quiet and unremarkable, without any record of serious prior violence. In early 1992, Dillingham began a relationship with Kristi Koslow, the teenage daughter of Jack Koslow and stepdaughter of Caren Koslow. Kristi, reportedly motivated by greed and anger toward her family, approached Dillingham and her boyfriend, Brian Salter, proposing a plot to kill her parents in exchange for inheritance money. Dillingham agreed to help, enticed by Kristi’s promise of a $1 million payout.

On March 12, 1992, Jeffrey Dillingham, along with Brian Salter, broke into the Koslow residence in the Rivercrest area of Fort Worth, Texas. Kristi Koslow had provided the alarm codes so the men could enter undetected. Inside, Dillingham and Salter attacked the sleeping couple. Dillingham beat Jack and Caren Koslow with a club, while Salter slit their throats. Jack Koslow managed to escape, bleeding heavily but alive, while Caren Koslow died from her wounds.

After the attack, the men stole $200 in cash and a $1,600 wristwatch before fleeing. Within days, investigators focused on Kristi after inconsistencies in her statements and her conspicuous lack of grief. Eventually, all three conspirators were arrested and charged with capital murder.

Salter accepted a plea deal for life imprisonment in exchange for testimony against Dillingham and Kristi. Dillingham rejected the plea deal and proceeded to trial, where he was convicted of capital murder and sentenced to death.

After spending seven years on death row, he was executed by lethal injection at the Huntsville Unit on November 1, 2000, at age 27.