The homicide of Casper native Teree Becker has been solved after more than 48 years, the Westminster Colorado Police Department announced Wednesday. Years of effort and genetic genealogy are credited for identifying Thomas Elliott as Becker’s killer.

Becker grew up in Casper with her parents, a brother and a sister. She was a graduate of Kelly Walsh High School and worked for a newspaper for a time. She moved to Denver shortly after graduating.

“Her family said that she often lived life on the edge. They said she never met a stranger and would hold a conversation with anyone. Teree enjoyed painting, and listening to music. Her favorite bands were Three Dog Night and Steppenwolf,” the statement read.

Becker was last seen alive on Dec. 4, 1975 when she was hitchhiking to Brighton, Colorado to see her boyfriend who was incarcerated at Adams County Jail. Her body was found two days later in a field near 100th Avenue and Lowell Boulevard in Westminster, Colorado.

“It appeared that Teree’s body had been dumped in the field, along with her clothing and personal items. During her autopsy it was determined Teree had been raped, and her cause of death was asphyxiation,” the police department said in a Wednesday Facebook post.

Elliott was in and out of prison. Shortly before he murdered Becker, he committed burglary in Lakewood, Colorado and served six years. He was shuffled through the prison system and was released in Las Vegas in 1981.

“After his release he proceeded to commit a crime against a child and received a ten (10) year sentence,” the statement read.

He was released in Las Vegas in 1991 and would go on to commit another murder before committing suicide on Oct. 30, 1991.

Becker’s case was reviewed multiple times over the years.

In 2003, a DNA sample of an unknown male was pulled from a piece of evidence. A profile was entered into the Combined DNA Index System (CODIS), but there was no match. Elliott had been adopted by his mother’s second husband, James Elliott, making genetic tracing difficult.

It wasn’t until 2013 when the Las Vegas Metro Police Department submitted an unknown male profile to CODIS that matched. In 1991, a woman was found raped and murdered in her apartment.

The Las Vegas Police Department was also without a suspect.

In 2018, the Westminster profile was deemed a good candidate for genetic genealogy, which identifies biological relationships between people. (It’s the same method that companies like 23andMe use to find a person’s relatives or ancestors.)

“Over the next five years, through the use of department research, Colorado Bureau of Investigation, Parabon Nanolabs (a genetic DNA lab), and Solved By DNA (a local Denver genealogist company) a suspect was ultimately identified; Thomas Martin Elliott,” the Westminster Police Department said.

The Las Vegas Police Department received consent to exhume Elliott’s body, which was interred at Southern Nevada Veterans Memorial Cemetery. Two members of the Westminster Police Department went to Las Vegas to witness the exhumation and collect remains for analysis.

Elliott was positively identified as the killer in December 2023.

“We are thrilled we were able to solve this cold case and hopefully bring closure to the friends and family of Teree Becker,” the Westminster Police Department said.