Polk County Sheriff’s Office Teams with Othram to Identify the Suspect in the 1986 Murder of Teresa Lee Scalf

Summary

In October 1986, 29-year-old Teresa Lee Scalf, a nurse at Lakeland Regional Health Medical Center in Polk County, Florida, was found murdered in her home. Teresa lived alone with her young son at the home. On October 27, 1986, when her son was away, Teresa was attacked and brutally murdered. The Polk County Sheriff’s Office (PCSO) responded to the scene of the crime and collected forensic evidence as part of their investigation. Among the evidence that was collected at the scene was blood that did not belong to the victim. PCSO detectives determined that the attack was sexually motivated. Ms. Scalf’s neck had been severely cut, and she had significant defensive wounds on her hands. There were no obvious suspects to the crime.

Throughout the course of the investigation, DNA was analyzed from the available forensic evidence and an STR profile was developed and entered into the Combined DNA Index System (CODIS), a consortium of local, state, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. There were no matches detected in the CODIS search and despite investigators' extensive efforts and thousands of man-hours, the identity of Ms. Scalf’s murderer went undetermined for more than three decades.

In 2022, the Polk County Sheriff’s Office teamed with Othram to determine if advanced DNA testing could help identify in new leads in the case. Forensic DNA evidence from the crime was sent to Othram’s laboratory in The Woodlands, Texas. Othram scientists used Forensic-Grade Genome Sequencing® to develop a comprehensive genealogical 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 Ms. 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 confirming 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. Connecting Douglas as a suspect was difficult because Douglas had no criminal history; therefore, his DNA profile was never obtained by law enforcement and was not entered into CODIS. Douglas was 33-years old at the time of Ms. Scalf’s murder. He died in 2008 from natural causes.

PCSO detectives informed Ms. Scalf’s family of the results of the investigation. PCSO Sheriff Grady Judd remarked, "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. Once our detectives had that, they were able to climb through a family tree that led to the identity of Teresa Scalf’s killer. I also want to thank Mr. Douglas’s son, who didn’t hesitate to assist our detectives."