Remains of Teen Girl Missing for Over 40 Years Found at Serial Killer’s Florida Home

Over forty years after a teenager went missing, her sister who reported her missing finally has some answers about what happened.

Margaret Johns was contacted by the Hernando County Sheriff’s Office last year about her sister, Theresa Caroline Fillingim, who was 17 at the time of her disappearance in 1980 in the Tampa, Florida area, WFLA reported. 

After she was contacted, Johns told the station, police met with her to obtain a DNA sample and establish a timeline.

Six weeks after she was initially contacted by police in July 2021, she learned that the DNA sample was a positive match. 

“It gives me peace because I know I didn’t lose her,” Johns, who first reported her sister missing, told the station. “That she was taken.”

According to a statement posted to Facebook Wednesday by the Hernando County Sheriff’s Office, the discovery of Fillingim’s remains “identified one of the two remaining unidentified victims in the Mansfield investigation from 1981.”

Theresa Caroline Fillingim, Remains of Florida Teen Missing for Over 40 Years Found at Serial Killer’s Home

Billy Mansfield Jr. is a convicted serial killer who was convicted and sentenced to life in prison for killing five women in California and Florida in 1982, WFLA reported. 

“In March and April of 1981, four sets of human remains were recovered from the Mansfield property located in Hernando County,” the statement explained.  “Two of the victims were immediately identified. The other two victims remained unidentified until now, where one of the victims has recently been positively identified.”

The Hernando County Sheriff’s Office did not immediately respond to PEOPLE’s request for comment.

Though the remains were collected in 1981 and sent to numerous labs in an attempt to identify them, the investigation was unsuccessful.

In 2020, a sample of the remains was sent to the University of North Texas, the sheriff’s office said. Then, officials were able to develop a complete DNA profile to enter into a national database, though a search of that database remained unsuccessful – but all hope was not lost.

“However, the complete DNA profile was reviewed, and it was determined that a sufficient DNA sample of the unidentified victim existed for further testing,” the statement continued. 

In addition to the University of North Texas, the authorities enlisted the help of Parabon Nano Labs, a DNA technology company in Virginia. Law enforcement agencies then used the company’s Snapshot DNA Phenotyping Service to produce “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,” the statement said. “Parabon’s research developed a profile that was utilized in the identification of the victim in this case.”

From there, the statement said, investigators were able to work to determine that Fillingim was one of the unidentified victims. 

Johns told WFLA that she plans to cremate the remains of sister and split the ashes with her brother.

“The sad part of it is my whole family never knew what happened to her. My dad died without knowing, my mom died without knowing… my sister died without knowing,” Johns told the outlet.

The victim’s sister also thanked the Hernando County Sheriff’s Office for following the cold case and “the diligent work… [they] did in bringing her home to me.”