Investigators identify human remains in 1973 cold case

SEATTLE - Investigators are seeking new leads and DNA information in a 1973 cold case with connections to Western Washington, after human remains were finally identified through genetic genealogy testing.

According to the Riverside County, California district attorney's office, forensics investigators have finally identified human remains found in 1974 as Rebecca Jean McMahan, also known as Becky McMahan and Becky Solis.

On Jan. 19, 1974, a body was found partially buried in the desert area of Desert Hot Springs, California. Detectives for years were unable to identify the remains, even with fingerprint analysis and dental records.

Genetic genealogy testing identifies cold case victim

In 2024, a regional cold case team reopened the case and sent bone samples of the remains to Othram.

There, forensics investigators built a genetic profile of the victim and checked it against an ancestry database, comprised of consumer DNA records. A possible match was found with a close relative in California, who they contacted and received a voluntary DNA sample from.

Investigators were then able to conclusively determine the human remains belonged to Rebecca Jean McMahan.

Who was Rebecca McMahan?

McMahan was 19 years old the last time her family saw her on July 3, 1973. She was last seen in public on June 11 of that same year in Bell Gardens, California, and had mentioned traveling to Palm Springs for a vacation.

Authorities say from 1969 to 1973, McMahan was known to have resided in Bellingham, Washington, as well as the California towns of Bell, Cudahy and Commerce.

McMahan is described as a white woman with long brown hair, hazel eyes, standing 5'3" or 5'4" and weighing 120–145 lbs. She is also described as having a tattoo reading "SS" on her ankle, and a butterfly tattoo on the right side of her chest.

What's next for the cold case investigation?

Authorities are asking anyone who knew McMahan or may have information on her disappearance to contact the Riverside County Regional Cold Case Homicide Team, either by contacting investigator Ebony Caviness at (951) 955-0257 or emailing coldcaseunit@rivcoda.org.

Additionally, investigators want more people to submit their DNA to reputable ancestry databases like Family Tree DNA and GedMatch, as forensics agencies use them to find genetic matches in criminal investigations.