WINTER HAVEN, Fla. − Each October, Teresa Scalf’s relatives prepare for the painful anniversary of her murder in 1986.

This year, for the first time, the family members will at least know who committed the vicious killing 37 years ago.

Through an investigation based on retained blood from the killer and public genetic databases, the Polk County (Florida) Sheriff’s Office identified Donald Douglas, a former neighbor of Scalf’s, as the murderer. Douglas, 33 at the time of the killing, died of natural causes at 54 in 2008, the sheriff's office said.

Scalf’s mother, Betty Scalf, and two of Teresa’s sisters joined Polk County Sheriff Grady Judd for a news conference Monday as Judd described how his agency solved the 37-year-old case.

“All I want to say is, I'm 84 years old,” said Betty Scalf, a petite, white-haired woman who uses a cane. “I lived to see this done. I think that’s why I lived so long.”

Scalf found the mutilated body of her daughter on Oct. 27, 1986, in the duplex she shared with her 8-year-old son in an unincorporated area of Lakeland, about 35 miles east of Tampa. Teresa Scalf, 29, worked the night shift as a trauma nurse at what was then Lakeland General Hospital.

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Betty Scalf had received a call saying her daughter, a single mother, had not shown up for work. Betty went to the duplex, used a credit card to open the locked door, and discovered her daughter’s body.

Judd, with the family’s permission, disclosed that Teresa had been repeatedly stabbed and nearly decapitated. Douglas lived just behind the duplex, Judd said, and investigators interviewed him and other neighbors at the time but never considered him a suspect.

Judd speculated that Douglas killed Scalf because he sought a sexual relationship with her and she rebuffed him. Family members said Scalf had mentioned “a creepy neighbor” shortly before her death but didn’t name or describe him.

Judd credited Detective Matthew Newbold with leading the effort to resolve the case after receiving it in 2015. Newbold kept a photo of Teresa Scalf on his desk and vowed to her family that he wouldn’t retire until he had identified her killer, Judd said.

“I hope it gives everybody comfort to know that we now know who did this,” said Pam Shade, Teresa’s sister. “We also would like to offer encouragement to other homicide victims: Don't give up. They (law enforcement) don't give up. And as long as they don't give up, you don't give up.”

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The investigation

Evidence at the scene suggested that Teresa fought back against her attacker, and investigators collected blood from her murderer. As technology advanced, the agency entered DNA taken from that blood into the FBI’s national database in the early 2000s but found no matches, meaning the killer’s DNA had not been entered.

Judd said Douglas had never been arrested.

“My prayer is that he had been in mental prison,” Judd said.

Newbold worked with Othram, a Texas company that specializes in developing genetic samples from crime scene evidence. Using publicly available DNA that people submit through such programs as 23andMe, the company helped create a family tree for the murderer, said David Nutting, a company representative who attended the news conference.

It was the 106^th publicly announced solution to an unsolved case through Othram’s DNA research, Nutting said. He said there are an estimated 330,000 unsolved murders in the United States.

After identifying Douglas as the murderer, sheriff's investigators contacted his son and asked for a DNA sample. He fully cooperated, Judd said, and was “mortified” to learn that his sample confirmed that Donald Douglas’ blood had been found at the scene of Scalf’s murder.

Judd said detectives originally investigating the case had seen no wounds on Douglas and had no reason to suspect him. Betty Scalf said heavy rain on the day of the murder washed away evidence and prevented search dogs from being able to find the killer’s trail from the duplex.

Joining Betty Scalf at the news conference were Teresa’s sisters — Shade, 61, and Lynne Scalf, 57. Teresa’s granddaughter, Teresa Wouters, 25, of Winter Haven, stood beside her great-grandmother, holding an arm around her.

Betty Scalf said that Teresa’s son could not attend because of the overwhelming emotion the anniversary brings.

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Family members said they did not know Douglas, who co-owned an electrical company with his brother. Lynne Scalf said she wished Teresa had described the “creepy” neighbor in a way that might have led the investigation to Douglas.

Newbold said investigators found no sign of forced entry at Scalf’s duplex. Betty Scalf said she thinks Douglas entered through a sliding glass door and was waiting for Teresa when she arrived home after finishing her overnight shift and sharing lunch with some co-workers.

'The most loving person'

Family members praised Judd and Newbold for not giving up on solving the murder. They offered affectionate memories of Teresa Scalf, who rose from an entry role as a phlebotomist to become a respiratory technician and then a registered nurse.

Shade is also a registered nurse and said many family members have gone into medical fields through Teresa’s influence and example.

“The first thing that I would like to say is Teresa was a wonderful person, the most loving person,” Shade said. “She didn't deserve it. Our family didn't deserve this.”

She added: “She started off at the bottom, nursing assistant. She went to respiratory school. She got her RN and was so proud. I've never seen anyone more proud. She said, ‘I did it. Pam, I did it.’ And she was dead a month later, after we had this conversation.”

Shade said a brother had died in a diving accident only a year and a half before Teresa’s murder.

Lynne Scalf said learning the identity of her sister’s killer does not bring an end to the family's grief but does relieve them of suspecting others who knew Teresa.

Betty Scalf, noting that the murder occurred four days before Halloween, said her daughter had promised to take her son out that day to buy a pumpkin for carving and had put a bike on layaway as his Christmas gift.

Lynne Scalf said her sister had two bumper stickers on her car − one urging the adoption of a 911 emergency call system, an idea that had not gained universal acceptance at the time, and the other saying: “Don’t take your organs to heaven. Heaven knows we need them here.”

The manner of Teresa’s death, and the delay of about 10 hours before her body was found, prevented her from having her organs harvested for donation.

“But she was the kind of person that if you asked her about something, she would engage in dialogue,” Lynne said. “So hopefully that encouraged some people to consider that pathway.”

Gary White can be reached at [email protected] or 863-802-7518. Follow on X @garywhite13.