LANCASTER (CBS SF/AP) — Serial killer Samuel Little, who confessed to over 93 murders across the country including at least three women in California, has died while being treated at a Southern California hospital.

The Department of Corrections said Little, 80, died at 4:53 a.m. Corrections spokeswoman Vicky Waters said there was no sign of foul play and his cause of death would be determined by the Los Angeles County Medical Examiner’s Office.

Labeled by the FBI as the most prolific serial killer in U.S. history, Little was serving three consecutive life-without-parole sentences from Los Angeles County for the deaths of three women that occurred in the late 1980s.

He was linked to the murders through DNA that was matched to evidence found in the crime scenes. He was convicted of first-degree murder by a Los Angeles County jury on Sept. 25, 2014, and was admitted to state prison on Nov. 24, 2014.

Little also had served two prior terms in state prison. On Aug. 14, 1985, he was admitted from San Diego County to serve four years for assault with a deadly weapon and false imprisonment. He was released to parole on Feb. 1, 1987, and was discharged from parole supervision on May 31, 1991.

Additionally, on Dec. 10, 2012, he was admitted from Los Angeles County for possession of a controlled substance. He was released to county probation supervision in April 2014.

In 2018, Little opened up to Texas Ranger James Holland, who had been asked to question him about a killing it turned out Little didn’t commit. During approximately 700 hours of interviews, however, Little provided details of scores of slayings only the killer would know.

A skilled artist, he even provided Holland with dozens of paintings and drawings of his victims, sometimes scribbling their names when he could remember them, as well as details such as the year and location of the murder and where he’d dumped the body.

Most of the slayings took place in Florida and Southern California.

Authorities, who continue to investigate his claims, said they have confirmed nearly 60 killings and have no reason to doubt the others.

“Nothing he’s ever said has been proven to be wrong or false,” Holland told the CBS news magazine “60 Minutes” in 2019.

The numbers dwarf those of Green River killer Gary Ridgeway (49), John Gacy (33) and Ted Bundy (36).

Almost all of Little’s victims were women, many of them prostitutes, drug addicts or poor people living on the edges of society. They were individuals, he said he believed, who would leave few people behind to look for them and not much evidence for police to follow.

Indeed, local authorities in states across the country initially classified many of the deaths as accidents, drug overdoses or the result of unknown causes.

Little strangled most of his victims, usually soon after meeting them during chance encounters. He drowned one, a woman he met at a nightclub in 1982.

Holland has described Little as both a genius and a sociopath, adding the killer could never adequately explain to him why he did what he did. Although known as an expert interrogator, Holland himself said he could only guess at why Little opened up to him.

The ranger did work tirelessly to create and maintain a bond with the killer during their hundreds of hours of interviews, bringing him favorite snacks such as pizza, Dr. Pepper and grits and discussing their mutual interest in sports. He also gave Little assurances that he wouldn’t be executed.

Holland would address Little by his childhood nickname, Sammy, while Little called Holland Jimmy and once told the Los Angeles Times he’d “found a friend in a Texas ranger.”

He told “60 Minutes” he hoped his confessions might exonerate anyone wrongly convicted of his crimes.

“I say if I can help get somebody out of jail, you know, then God might smile a little bit more on me,” he said.

A transient who traveled the country when he wasn’t in jail for larceny, assault, drugs or other crimes, Little said he started killing in Miami on New Year’s Eve 1970.

“It was like drugs,” he told Holland. “I came to like it.”

His last killing was in 2005, he said, in Tupelo, Mississippi. He also killed people in Tennessee, Texas, Ohio, Kentucky, Nevada, Arkansas and other states.

Kentucky authorities finally caught up with him in 2012 after he was arrested on drug charges and his DNA linked him to three California killings.

When he began recounting the other slayings, authorities were astounded at how much he remembered. His paintings, they said, indicated he had a photographic memory.

One killing was solved after Little recalled the victim wore dentures. Another after he told Holland he’d killed the victim near a set of unusual looking arches in Florida. A victim he met outside a Miami strip club in 1984 was remembered as being 25 years old with short blond hair, blue eyes and a “hippie look.”

As he continued to talk, authorities across the country rushed to investigate old cases, track down relatives and bring closure to families.

Little revealed few details about his own life other than that he was raised in Lorain, Ohio, by his grandmother. Authorities said he often went by the name Samuel McDowell.

He was married once, Little said, and involved in two long-term relationships.

He claimed he developed a fetish for women’s necks after becoming sexually aroused when he saw his kindergarten teacher touch her neck. He was always careful, he added, to avoid looking at the necks of his wife or girlfriends and never hurt anyone he loved.

“I don’t think there was another person who did what I liked to do,” he told “60 Minutes.” “I think I’m the only one in the world. And that’s not an honor, that is a curse.”

© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.