The man authorities say was the most prolific serial killer in U.S. history has died at 80.

California corrections department spokeswoman Vicky Waters said Samuel Little died Wednesday. He had been serving a life sentence at a California prison after being convicted of three counts of murder in 2013.

It was not until 2018 that Little began to reveal to Texas Ranger James Holland that he had killed 93 people in 19 states between 1970 and 2005. Almost all were women, mainly prostitutes, drug addicts and others living on the margins of society.

MORE: Samuel Little confesses to killing two women in Cincinnati

Authorities say a woman's skeletal remains were identified 44 years after her murder.

According to the Jackson County Sheriff's Department, the woman long known to investigators as "Escatawpa Jane Doe," has been identified as Clara Birdlong.

Birdlong was found in 1977 at a Mississippi construction site and investigators believe she was a victim of the most prolific killer in U.S. history, the late Samuel Little.

The department said hunters found Birdlong's remains near a highway in Jackson County on Dec. 27, 1977. She was a short Black woman with a distinctive front gold tooth and probably wore a wig.

Officials say she was discovered about three or four months after she was killed.

Authorities said throughout the years, "several facial reconstructions and computer composites were created in an effort to help identify her."

A breakthrough came in January 2021 when authorities in Mississippi contracted a Texas DNA research facility to create a family tree based off Birdlong's DNA. They then traced it to a cousin in Mississippi, who connected them to her 93-year-old grandmother.

The grandmother told investigators that her cousin was born around 1933 and went missing from Leflore County sometime in the 1970’s.

"Another distant cousin in Texas said Clara went by the nickname “Nuttin,” and described her as a small woman who had a gold front tooth and wore a wig," the sheriff's department said. "The cousin also recalled Clara disappeared in the 1970’s."

In August, a woman in LeFlore County who remembered Birdlong told investigators that the victim the county in the 70’s with a Black man "who claimed to be passing through Mississippi on his way to Florida."

Birdlong was never seen or heard from again, investigators said.

In September, investigators confirmed that Birdlong's DNA matched that of the grandmother.

The sheriff's department considers Little to be the prime suspect.

Her cause of death is undetermined.