Investigators in Texas and California used DNA evidence to link a retired McLennan County truck driver to two killings in the 1990s in East Texas and California, a search warrant affidavit says.
Douglas Thomas, 67, was charged with murder Friday in the 1993 death of Sherri Herrera, whose body was found on the side of the highway in Riverside County, California, according to a press release from the Riverside County District Attorney’s Office. Thomas had been arrested by the Texas Rangers last month on a murder charge in the 1992 death of Shenda Hayes, whose body was found near a highway rest stop in Titus County, in northeast Texas. The affidavit says investigators from the Rangers’ cold case unit obtained a DNA sample from Thomas matching DNA found at the scene of both slayings.
The press release states Thomas traveled extensively through the country in his 40-plus-year career as a truck driver.
The affidavit says the body of Herrera, a 30-year-old mother of four, was discovered in the desert next to Interstate 10 in March 1993 in California. Her body was found with evidence of sexual assault and it is believed she was strangled with a belt, the affidavit says. The affidavit states Herrera was a “known prostitute” and was known to work highway rest stops in Tulare County, California.
The affidavit says Hayes’ body was found at a rest area along I-30 in April 1992 in Titus County with evidence of sexual assault. It is believed Hayes was strangled with a device made of wire and cord, the affidavit says. The affidavit says Hayes was also a “known prostitute.”
DNA samples from scenes were uploaded into the Combined DNA Index System, a national forensic DNA database, the affidavit says. In 2007, a match was made connecting the deaths of Herrera and Hayes, meaning that DNA from a single person was found at both scenes, the affidavit says.
In 2020, investigators in California began conducting forensic genealogy to look for genetic matches to the DNA sample, the affidavit says. Investigators created a “family tree” and found six descendants living in the Waco area who were in the right genetic range for comparison to the DNA samples investigators had collected, the affidavit says. According to the affidavit, investigators from California contacted the Texas Rangers in April and asked the Rangers to contact the descendants and ask for a consensual DNA sample.
The affidavit says Thomas consented and gave a DNA sample to the Rangers in April, which was processed and completed last month and indicated Thomas was a match for the DNA samples found at the scenes.
McLennan County Jail records show Thomas was charged with first-degree felony murder in May and remained in the jail Tuesday on bond totaling $2 million. The press release says Thomas will be prosecuted in Texas first in Hayes’ killing, then the DA’s office in Riverside County will request he be extradited to California to stand trial in Herrera’s death.