A man has reportedly confessed to killing up to 90 people over four decades across multiple US states.
In a report released this week, the Federal Bureau of Investigation (FBI) said Little was able to evade detection by preying mainly on drug addicts and prostitutes in a murder spree that stretched from coast to coast.
Little so far has confessed to killing more than 90 women
A former boxer, Little would stun his victims with a powerful blow before strangling them, meaning many of the deaths were attributed to drug over doses or natural causes, the agency said.
A large number of the murders were also committed in the 1970s and early 1980s, before DNA profiling was common practice.
The FBI is now working to match his confessions to the deaths of 34 women from 1970 to 2005. Little, also known as Samuel McDowell, was arrested at a homeless shelter in Kentucky in 2012 and taken to California where he was wanted on a drugs charge.
Once there, DNA evidence linked him to three murders in Los Angeles between 1987 and 1989. All three women were beaten and strangled.
Little was convicted and sentenced to life in prison in 2014 but transferred to a Texas prison in connection with an investigation into another murder.
Bobby Bland, a district attorney in the state, said Little eventually confessed to the 1994 murder of Denise Christie Brothers in Odessa, Texas.
Shortly afterwards, a Texas ranger was able to gain Little’s trust and the killer began confessing to dozens of other murders committed between 1970 and 2005.
A total of 90 murders in all, of which law enforcement has so far verified 34 killings.
“Little will be confirmed as one of, if not the most, prolific serial killers in US history,” Mr Bland said.
The deadliest known US serial killer is believed to be Gary Ridgway, the so-called “Green River Killer” convicted of 49 murders who is serving a life sentence in Washington state.
According to the FBI, Little “remembers his victims and the killings in great detail” but is “less reliable, however, when it comes to remembering dates.”
“Talking with him, you can hear he actually gets excited about describing his homicides and describing how he strangled his victims,” Bernie Nelson, a police detective, told the Washington Post.
“He looked you right in your eye and said he couldn’t help himself. He’s a monster.”
The FBI said Little is in poor health and is likely to spend the remainder of his days in prison in Texas.
The reported confessions come after Little was charged in July with the 1994 murder of Denise Christie Brothers in Ector County, Texas.