A male individual has been convicted in two cold cases in Mesa—a strangulation murder and a rape—dating back over thirty years, following the confirmation of his guilt through DNA evidence, as announced by the Maricopa County Attorney’s Office on Friday morning.
Thomas David Cox, aged 60, entered a plea of guilty to first-degree premeditated murder and aggravated assault on February 2. The county attorney’s office disclosed that Cox received a life sentence for the murder charge and a 10-year sentence for the assault, with both sentences to run concurrently. He will be eligible for parole after serving 25 years, having already spent close to two years in jail.
The incident dates back to October 16, 1989, when Mesa police conducted a welfare check on a 22-year-old woman who had failed to show up for work. She was discovered strangled to death with an electrical cord and bearing signs of physical assault.
It was revealed by Mesa police that the victim had also been sexually assaulted during the incident at her residence, which was located adjacent to Cox’s mother’s apartment, as reported by The Arizona Republic in 2022. The victim, identified as Susan Amy Morse in an article dated October 18, 1989, was a divorced individual who had moved into an apartment complex near Southern Avenue and Country Club Drive three months prior to her tragic demise. Morse, originally from Cave Creek and employed in Tempe, was described by a colleague as a sociable and cheerful person.
In an interview published on September 27, 1990, Morse’s father expressed concerns about the safety of young women until the perpetrator was apprehended. Subsequently, on November 13, 1990, Mesa police responded to a sexual assault incident within the same apartment complex, where a single mother’s residence was broken into, and she was sexually assaulted, with her VCR and cash stolen.
DNA evidence was collected from the crime scene, leading to the creation of a profile for an unidentified male assailant. In November 2002, Mesa police connected both crimes through a DNA match, although no matches were found in the FBI’s offender database.
Nearly two decades later, Cox was identified as a suspect through advanced DNA testing conducted by the federally funded Sexual Assault Kit Initiative Project. His DNA matched samples from both the murder and sexual assault cases, and his palm print was a match for a print found at the rape victim’s apartment.
According to previous reports by The Republic, advanced DNA technologies were utilized to establish a familial connection linking Cox to the crimes. In April 2022, Cox was extradited from Colorado Springs, Colorado.
County Attorney Rachel Mitchell emphasized the prolonged agony experienced by victims and their families in cold cases, highlighting the defendant’s heinous acts and the necessity for him to face life imprisonment for his crimes.