POLK COUNTY, Fla. — Polk County Sheriff Grady Judd said Monday that a 1986 homicide has been solved.

The sheriff's office said detectives determined who killed 29-year-old Teresa Lee Scalf of Lakeland 37 years ago.

With assistance from a private lab specializing in forensic genetic genealogy in cold case investigations, Judd said Donald Douglas was responsible for the death of Scalf.

Douglas died of natural causes in 2008 at the age of 54. He was 33-years-old at the time of the murder, which happened Oct. 27, 1986.

Douglas had no criminal history and his body was cremated after he died, the sheriff's office said. His DNA was never able to be obtained by law enforcement and put into a database for comparison. 

He lived directly behind Scalf at the time of her murder. Douglas had been interviewed by detectives in 1986 during a routine canvass, but at that time, there was no evidence to link him to the murder. 

The direct connection to the identity happened after detectives obtained a sample of DNA from a son of Donald Douglas. The results of a genetic analysis of the DNA confirmed that the blood found at the murder scene belonged to Donald Douglas.

Members of her family were at Monday's news conference, which you can watch below.