Victim Lesia Michell Jackson. Credit: MCSO
M-Vac technology has helped cold case detectives in Montgomery County, Texas solve their oldest homicide case—the 1979 abduction, rape and murder of 12-year-old Lesia Michell Jackson.
After spending a day at her neighborhood pool, Jackson disappeared before she could return home. Six days later, on Sept. 13, 1979, an oilfield worker found her body in a heavily wooded area. A subsequent autopsy revealed Jackson had been raped.
The Montgomery County Sheriff’s Office (MCSO) followed leads for years but eventually all were exhausted and the case went cold.
A new spotlight was shined on the case when the then-newly created MCSO Cold Case Homicide Squad took over the investigation in May 2005. As with all cold case units, the team kept apprised of new forensic innovations and technological advancements that could have an impact on a case.
In October 2021, they found one—the M-Vac wet-vacuuming system.
The M-Vac aggressively sprays a sterile solution onto a surface and simultaneously applies vacuum pressure to collect the solution and whatever DNA material is present on the surface. The solution and DNA material are then run through a filter or a microcentrifuge.
When investigators used the system—which M-Vac CEO Jared Bradley describes as “a mini-hurricane”— on Jackson’s clothing, they were able to retrieve previously impossible DNA samples. For years, detectives thought there could be evidence on the victim’s clothing, but traditional swabbing methods proved to be unsuccessful.
That lines up with a 2020 study by the FBI in which the agency concluded M-Vac should be considered an alternative DNA collection method. In the study, the M-Vac yielded consistently greater nDNA and mtDNA yields than traditional wet‐swab methods. On previously swabbed substrates—like Jackson’s clothing—the M-Vac recovered additional DNA on 9 out of 10 surfaces, the only exception being satin-painted drywall. At minimum, the M-Vac recovered at least as much as swabbing, but at maximum, the vacuum system recovered 46x more.
With a viable DNA sample in hand, Texas Department of Public Safety forensic scientists were able to identify an unknown male DNA profile in April 2022. The profile hit in CODIS to a local man named Gerald Dewight Casey.
Casey, however, was already deceased. He was executed in April 2002 by the state of Texas for the 1989 murder of Sonya Lynn Howell. Howell was the roommate of Daryl Pennington, who Casey planned to steal a load of guns from. During the burglary, Casey beat Howell, shot her nine times and dumped her body in the woods.
Even before Howell’s murder, Casey had a rap sheet that included assaulting a police officer, burglary and multiple drug charges. Now, that sheet includes a second murder.
On July 8, forensic scientists matched a 1989 blood sample taken from Casey to the DNA evidence found by M-Vac.
“The tenacity and diligence in solving this case by a dedicated team is a reminder to our public and to those who commit crimes in our communities that we will never cease our efforts to solve the hardest of cases and bring closure to traumatized families,” MCSO said in a statement. “The Montgomery County Sheriff’s Office will continue to explore future advances in technology that can assist us in solving other cases currently under investigation.”