After 4 decades, DNA identifies Tampa teen as victim of serial killer Billy Mansfield

It’s been 41 years since Hernando County sheriff’s deputies descended on a 6-acre junkyard in Spring Hill’s Weeki Wachee Acres neighborhood, ready to start digging around the home neighbors now call the “House of Horrors.”

But on March 16, 1981, the day excavators and deputies started digging, it was simply the family home of Billy Mansfield Jr., the eldest son of a convicted child molester who took after his father in ways beyond their shared name.

In just a few weeks of digging, deputies unearthed the remains of four women on Mansfield’s property. Two were quickly identified but, year after year, the other two women have remained nameless.

That changed Wednesday afternoon, when the Hernando County Sheriff’s Office issued a formal announcement that one of the two victims has been positively identified as Theresa Caroline Fillingim. Fillingim was just a week away from her 17th birthday when her sister, Margaret Johns, reported her missing to Tampa police on May 16, 1980.

Johns did not immediately respond to requests for comment.

Now, thanks to a new partnership with the University of North Texas and the Virginia-based DNA technology company Parabon Nano Labs, Hernando investigators said they can conclusively say Fillingim’s body was the third one pulled from the grounds around Mansfield’s home on April 3, 1981.

Investigators also worked alongside renowned expert Erin Kimmerle and her colleagues in the forensic anthropology department at the University of South Florida.

Fillingim’s remains had been sent to numerous labs over the years, but experts didn’t succeed in developing a DNA profile until 2020, the Sheriff’s Office said. That sample was then sent to the University of North Texas to search for a match in a national database, but that effort once again proved fruitless.

This year, though, researchers told the Sheriff’s Office they wanted to try again — this time using Parabon’s new “Snapshot DNA Phenotyping” services to create their own profile of the woman who was killed instead of simply looking for her match.

“Using DNA evidence from this investigation, Snapshot produced trait predictions for the associated victim. Individual predictions were made for the victim’s ancestry, eye color, hair color, skin color, freckling, and face shape,” Wednesday’s statement from the Sheriff’s Office said.

That profile allowed investigators to generate their own “actionable leads” for the cold case, the statement said. A DNA sample from Fillingim’s sister confirmed her identity, according to the Sheriff’s Office, “finally bringing peace to the victim’s family.”

Mansfield Jr. had already racked up a laundry list of crimes including battery, kidnapping and sexual assault when he met 30-year-old Rene Sailing at a tavern in California on Dec. 6, 1980. The two left together, and the following morning officers found Sailing’s body in a drainage ditch, riddled with bullet holes. Mansfield Jr. was arrested on a first-degree murder charge days later. After a mistrial and an attempted prison escape, he was convicted of raping and strangling Sailing.

The publicity from the California case led an anonymous tipster to call Hernando authorities and ask them to search Mansfield Jr.’s home for Sandra Graham, a 21-year-old Tampa woman who went missing on April 17, 1980.

The first skeleton buried on the grounds was unearthed the next day — on March 17 — but it only was identified by experts as a white woman in her 20s and still remains a “Jane Doe.” A week later, another skeleton was discovered — this time identified as 15-year-old Elaine Zeigler, a tourist from Ohio who disappeared from a nearby campground on New Year’s Eve in 1975. On April 3, authorities pulled from the ground what they now know was 16-year-old Fillingim’s body. And four days later, the tipsters’ predictions came true when Sandra Graham’s remains were finally recovered.

Court documents said the women all were sexually assaulted by both Mansfield Jr., his younger brother Gary, and their father, William Mansfield Sr. It was Mansfield Jr., though, who would eventually kill the women and often dismember them, court records said.

Mansfield Jr. eventually pleaded guilty to killing all four of the women found at his home, and also pleaded guilty to the attempted sexual battery of a fifth woman. He is serving a life sentence in California.