MONTGOMERY COUNTY, Texas — Family members of a girl found dead in Montgomery County more than four decades ago finally know who killed her.
Twelve-year-old Lesia Mitchell Jackson disappeared from her neighborhood off of FM 1485 after spending a day at a community pool.
A week later, on September 13, 1979, an oilfield worker found her body in a heavily wooded area along a pipeline near Exxon Road in Conroe.
An autopsy revealed Lesia had been sexually assaulted before she was murdered, according to the Montgomery County Sheriff’s Office.
Despite an extensive investigation that lasted for years, the case eventually went cold.
In 2005, MCSO created the Cold Case Homicide Squad and they took over the investigation. Last October, detectives from the unit sent DNA from Leisa's clothing to Texas DPS forensic scientists who used a new technology called "M-Vac" to develop a DNA profile.
They got a hit on the FBI's CODIS database that identified Leisa's killer as Gerald Dewight Casey.
Further investigation revealed Casey had been executed in 2002 for another murder.
MCSO says this is the oldest cold case ever solved by their department and they credit "tenacity, diligence and a dedicated team."
The 1989 murder case
Casey, 34, and his accomplice, 36-year-old Carla Smith, cooked up a plan in 1989 to steal a bunch of guns from a man they knew so they could sell them and use the money to move to Florida.
On July 10, they discovered Daryl Pennington, the owner of the guns, was at work and his roommate, Sonya Lynn Howell, was home alone.
Smith later testified that she and Casey agreed that they would leave Howell in the woods so Pennington would think she stole the guns.
Instead, the victim was beaten with a telephone, shot nine times and dumped in the woods.
Witnesses later identified Casey as the person who sold them guns stolen from Pennington.
Smith testified against Casey at his 1991 trial and he was convicted of capital murder and sentenced to death.
Even before Howell's murder, Casey had a long rap sheet that included assaulting a police officer, burglary and multiple drug charges. He'd spent time in and out of prison between 1976 and 1989.
Casey was 47 when he was executed by lethal injection on April 18, 2002.
Smith was convicted of robbery for her role in the case and sentenced to 10 years in prison.
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