In October 1986, a 29-year-old nurse at Lakeland Regional Health Medical Center in Polk County named Teresa Scalf was found brutally murdered in her home. There were no obvious suspects to the crime. The Polk County Sheriff’s Office (PCSO) collected forensic evidence, including blood found at the crime scene that did not belong to the victim.
Over the ensuing years, DNA was analyzed from the available forensic evidence but there were no matches detected in the national DNA database, i.e., the FBI’s Combined DNA Index System (CODIS). Despite investigators’ extensive efforts and thousands of man-hours, the identity of Scalf’s murderer remained a mystery.
That is until 2022 when the Polk County Sheriff’s Office engaged Othram, a national leader in the burgeoning investigatory field of forensic genetic genealogy to see if advanced DNA testing could help develop new leads in the case.
Blood samples found at the crime scene were sent to Othram’s laboratory in The Woodlands, Texas. Othram scientists used Forensic-Grade Genome Sequencing to develop a comprehensive DNA profile from the DNA of the unknown male suspect. Othram’s in-house forensic genetic genealogy team used the profile to produce new investigative leads, which were provided to PCSO detectives.
Using these leads, PCSO detectives conducted interviews with distant relatives of the unknown suspect. These interviews allowed PCSO detectives to narrow their search to a now deceased man who lived directly behind Scalf at the time of her murder.
The suspect’s son cooperated with the investigation and provided a reference DNA sample that was compared with the male suspect DNA collected from the crime scene in 1986. Results of the comparison confirmed a parent-child relationship, thereby indicating that the blood found at the murder scene belonged to Donald Douglas.
Douglas was interviewed by detectives in 1986 during a routine canvass. But at that time, there was no evidence to link him to the murder. Forensic DNA typing was just beginning to be developed, and at the time of the murder, there was no laboratory offering DNA testing and the concept of a national DNA database had yet to be considered.
Over time, DNA typing became established, but connecting Douglas as a suspect was difficult. Douglas had no criminal history, and therefore, his DNA sample was never obtained by law enforcement. Thus, his profile was not entered into CODIS. Douglas was 33 years old at the time of Scalf’s murder. He died in 2008 from natural causes.
At a news conference earlier this year announcing the identity of the killer, Scalf’s 84-year-old mother remarked: “I lived to see this day. I think that’s why I lived so long.”
“We are extremely grateful for the assistance from Othram, who provided us with the missing element in this investigation, and ultimately enabled this case to finally be solved,” said PCSO Sheriff Grady Judd. “Once our detectives had that, they were able to climb through a family tree that led to the identity of Teresa Scalf’s killer.”
Forensic genetic genealogy is a revolutionary investigative method that marries forensic genetic analysis with genealogical research to help identify unknown individuals, often in cases that have gone cold for years. It merges two distinct fields — forensic genetic science, particularly DNA profiling, and genealogy, the study of family histories — allowing law enforcement to crack cases that were previously unsolvable.
Historically, the most common form of DNA testing used by forensic laboratories analyzed only a very small portion of human DNA, known as short tandem repeats (STRs).
In the late 1990s, the FBI chose 13 STRs as the core set for a DNA identification profile. These 13 STRs (now up to 20 STRs) are analyzed from DNA from crime samples and known reference samples and entered into CODIS. CODIS is the general term used to describe the FBI’s national DNA database program that supports local, state and national DNA indexes to develop investigative leads in an expeditious manner.
But this approach has its limitations. To be successful, the DNA profile from the donor of the crime scene evidence has to be in the FBI’s database, which most likely requires some previous encounter with law enforcement. That’s where forensic genetic genealogy comes into play.
By establishing a genetic association to people who voluntarily have donated their DNA to generate profiles comprised of a different type of markers known as SNPs (or single nucleotide polymorphisms) to public genetic genealogy databases, law enforcement investigators can build a family tree or trees that could lead to near or distant relatives of the unknown source of crime scene evidence or unidentified human remains.
While forensic genetic genealogy is an obvious and powerful application of this new forensic DNA technology, there are investigative applications as well.
A recently published peer-reviewed research paper that compared the use of traditional forensic anthropology — analysis of skulls and bones — and genetic ancestry analysis concluded that while forensic anthropology can provide valuable insights, its accuracy is limited due to the factors such as limited or partial data.
“In contrast, genomic analyses offer a more robust approach, leveraging hundreds to thousands of markers to provide nuanced ancestry estimations. The discrepancies observed highlight the importance of refining current practices and enhancing interdisciplinary collaboration between forensic anthropology and genomics,” the report concluded.
The point is that these advanced capabilities leverage far more genetic information than the standard systems. That means more investigative leads can be developed, which in turn means more cases can be solved via advanced forensic DNA methods, like Forensic Grade Genomic Sequencing, than has ever been possible in previous years.
Founded in 2018, Othram is now the nation’s leading provider of service and technology for forensic genetic genealogy labs. Othram’s mission is to develop technology that can bring certainty to law enforcement investigations such as those that involve unsolved murders, disappearances of missing persons and identification of human remains.
“Justice is not a luxury,” said Dr. Kristen Mittelman, Chief Development Officer at Othram. “It’s a basic human right.”
To date, Othram has been publicly credited with helping to solve nearly 400 cases, including murders, rapes and unidentified human remains. In Florida, the company has been credited with helping identify several dozen murder suspects and human remains in cities and counties including Palm Beach, Boynton Beach, Pensacola, Hillsborough, St. Pete, Orlando, Winter Park, Flagler Beach, Collier County and Jupiter. (For a complete list of the locations and details of solved cases in Florida, go to www.DNAsolves.com.)
Still, these successes are just a drop in the bucket to what needs to be done. There are an estimated 250,000 unsolved homicides in the United States and as many as 75,000 unidentified human remains. Funding remains an issue. It costs about $10,000 to conduct a forensic genetic genealogy investigation. With budget constraints at most state and local law enforcement agencies, the additional cost can be a hurdle.
But recognizing the scope of the problem and the potential success of this investigative approach, the Legislature earlier this year passed, and Gov. Ron DeSantis signed, the first-of-its-kind legislation that created a nonrecurring pool of $500,000 for the 2024-2025 fiscal year to employ forensic labs like Othram to assist in solving cold cases. The Legislature is expected to revisit the funding needs again next year.
“I’d like to thank the Florida Legislature, and in particular, Sen. Jennifer Bradleyand Rep. Adam Anderson, for recognizing the potential of DNA testing in helping solve these cold cases,” Mittelman said. “Advanced DNA testing is currently being used sparingly but it’s the future method of choice and it can deliver impact at scale.”
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