Westminster Police Department
Teree Becker was killed in 1975 and police announced her killer's identity on Wednesday.
CNN  — 

Nearly 50 years after a woman’s body was found dumped in a Colorado field, her killer has finally been identified, police announced Wednesday.

Teree Becker was last seen on December 4, 1975, Westminster, Colorado, police said in statement. The 20-year-old was reportedly hitchhiking to see her boyfriend at the Adams County Jail in Brighton, Colorado. Two days later, a couple found her body and personal items in a field.

An autopsy revealed she had been raped and the cause of death was asphyxiation, the statement said. Becker’s killer was never found. As the years went on, her case was reviewed several times, without any breakthrough.

The situation changed with the advance of forensic science. In 2003, the Colorado Bureau of Investigation was able to extract the DNA of an unknown male from a piece of evidence that had been collected in connection with Becker’s rape, police said. The man’s profile was entered into a DNA database, but there was no match.

But, 10 years later, it fit a DNA profile submitted by the Las Vegas Metro Police Department while they were reviewing another cold case. That case was from 1991 and involved a woman who had been found raped and killed in her apartment.

The DNA revealed the same man had killed both Teree Becker and the woman in Las Vegas, according to police, but they still didn’t have a suspect in either case.

That changed last year.

After five years of using genetic genealogy, which combines DNA testing with traditional genealogical methods to identify people or discover their ancestry, the Colorado Bureau of Investigation in partnership with a genetic DNA lab and a genealogist company managed to identify a suspect, Westminster police said.

In October, Las Vegas police had the body of Thomas Martin Elliott exhumed on the probability he was the suspect in both killings. A Westminster police detective witnessed the exhumation and the bones were sent for analysis.

After nearly half a century, police identified Elliot late last year as the unknown male who killed both Becker and the woman in Las Vegas.

Authorities discovered Elliot had been in and out of prison over the years for various offenses, including doing time for burglary and committing a crime against a child. He died by suicide in 1991 for unknown reasons, soon after the Las Vegas homicide.

Westminster police said they hope finally finding Becker’s killer brings closure to her family and friends.

Becker grew up in Wyoming and moved to the Denver metro area after graduating high school, according to the police statement. It said her family described her as a “free spirit” who “never met a stranger and would hold a conversation with anyone.”