Johnston was 68 years old and had just retired from the state welfare department a few months before her death in 1976, according to contemporary reporting by the Sapulpa Daily Herald. Johnston’s killer apparently forced his way into her Oklahoma City duplex, beat her and sexually assaulted her before strangling her to death.
The Oklahoma City Police Department’s new genealogical evidence indicates the killer was Charles Droke, who was 28 at the time.
Droke was never connected to the crime before he was shot to death by his younger brother, Edwin, in 1989. Edwin claimed he was defending himself and his family from Droke, but a jury convicted him of murder and sentenced him to death. He died by suicide the day after his sentencing.
After going cold for decades, the search for Johnston’s murderer picked up again in 2004, when scientific breakthroughs allowed OKCPD to develop a genetic profile of the killer based on evidence collected at the crime scene. The profile wasn’t a match to anyone in the FBI’s database of DNA collected from convicted offenders.
But, the FBI’s database isn’t the only large collection of genetic profiles. As more people have submitted their DNA to genealogy sites, law enforcement has begun to use some of those databases to trace genetic evidence back to the people it came from. Often, offenders are identified because someone in their family has submitted a genetic sample to a genealogy site.
The largest genealogy sites, Ancestry.com and 23andMe, don’t share customer data with law enforcement unless a court orders them to share specific records. Many high-profile genealogical investigations use a database called GEDmatch.
This practice — forensic genetic genealogy — was first used in 2016 to catch a man who killed two women in Phoenix in the early 1990s. Its most famous use came in 2018 when investigators identified the Golden State Killer, who committed at least 13 murders and 51 rapes in California in the 1970s and 80s.
Johnston’s murder is the first case the Oklahoma City Police Department has solved using forensic genetic genealogy. The department has been working with a private forensic DNA company since spring of 2023 to narrow down suspects in cold cases. Investigators identified Droke as the killer based on similarities to samples his relatives submitted to genealogy sites.
An OKCPD spokesperson said the relatives identified using forensic genealogy worked with investigators. They received further confirmation by matching the DNA Droke left at the scene of Johnston’s murder to DNA in the evidence from his own murder.
“It is very important that this is solved,” Johnston’s granddaughter, Leslie Sullenger, said in a video posted to OKCPD’s social media. “I feel an inner peace now.”
This same technology can be used to identify unknown victims of crimes. The City of Tulsa is working with another forensic DNA company to name unidentified victims of the 1921 Tulsa Race Massacre. Earlier this year, the city announced it had found and notified one victim’s family, who didn’t know where he had been buried for more than a century.
This report was produced by the Oklahoma Public Media Exchange, a collaboration of public media organizations. Help support collaborative journalism by donating at the link at the top of this webpage.
