Samuel Little's depravity is matched only by his prodigious memory.

Little, a California inmate pronounced by the FBI the most prolific serial killer in U.S. history, has confessed to 93 slayings committed across the country between 1970 and 2005, recounting the crimes with astonishing, near-photographic detail and even drawing color portraits of dozens of the women he strangled.

His case, featured on "60 Minutes" on Sunday, has offered a frightening look inside the mind of a killer and the wrongheaded assumptions on the part of law enforcement that enabled him to escape justice for so long.

Little, who is 79 and has been behind bars since 2012 for several killings, preyed on prostitutes, drug addicts and other women on the margins, many of them black like Little himself, and many of the deaths were originally deemed overdoses or attributed to accidental or undetermined causes. Some bodies were never found.

In a case out of Tennessee, for example, Martha Cunningham's body was found bruised and nude from the waist down in the woods in 1975, her pantyhose and girdle bunched around her knees. Detectives initially attributed her death to natural causes; the cause was later classified "unknown."

But in 48 straight days of interviews with Texas Ranger James Holland, who kept the killer supplied with pizza and Dr. Pepper, Little offered a wealth of details that were used to corroborate his accounts. One woman wore dentures, for example. Another was killed near a set of arches in Miami.

Holland noted that Little liked to draw and gave him art supplies. Little produced more than 30 portraits of his victims.

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FILE - This combination of undated sketches provided by the FBI shows drawings made by admitted serial killer Samuel Little, based on his memories of some of his victims.
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Serial killers are often world-class liars and manipulators who crave notoriety and exaggerate or confess to crimes they didn't commit, according to criminal justice experts. But Little stands apart.

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"I would be suspicious of believing him, except it was actually corroborated," said Marina Sorochinski, a professor of criminal justice at Mercy College in New York.

As Holland said on "60 Minutes": "Nothing he's ever said has been proven to be wrong or false. We've been able to prove up almost everything he said."

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This combination of undated sketches provided by the FBI shows drawings made by admitted serial killer Samuel Little, based on his memories of some of his victims.
AP

Law enforcement authorities in several states have verified 50 of his confessions so far and are scrambling to link dozens more cold cases to his recollections.

All told, he is believed responsible for more killings than Ted Bundy, John Wayne Gacy and Jeffrey Dahmer combined.

Little's modus operandi made it hard to link him to victims. The former boxer often delivered a knockout punch to women, authorities said, then strangled them. He would dump their bodies and soon after leave town.

He claimed to have killed in 19 states, with about 20 slayings in Los Angeles alone.

In a 2018 prison interview with New York magazine's website The Cut, Little said he considered his victims his "babies." Asked how it felt to kill the women, he said: "Oooeee, it felt like heaven. Felt like being in bed with Marilyn Mon-roe!"

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FILE - In this Monday, Nov. 26, 2018 file photo, Samuel Little, who often went by the name Samuel McDowell, leaves the Ector County Courthouse after attending a pre-trial hearing in Odessa, Texas. Little, who has confessed to killing more than 90 women across the U.S. has been indicted in Cleveland for the strangulation deaths of two women decades ago. Cuyahoga County Prosecutor Michael O’Malley on Friday, May 31, 2019 said 78-year-old Samuel Little confessed to killing 21-year-old Mary Jo Peyton in 1984 and 32-year-old Rose Evans in 1991.(Mark Rogers/Odessa American via AP, File)
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