Samuel Little, 79, made the confessions to a Texas ranger while serving time for the murder of three Los Angeles women.
The convict has so far admitted to a total 93 murders – mostly women – on dates between 1970 to 2005, the FBI said.
So far the bureau has linked him to 50 deaths, though it believed all of the convicted killer’s confessions were credible.
It said the man, who had a history of criminal activity dating back to his teenage years, chose to kill “marginalized and vulnerable women who were often involved in prostitution and addicted to drugs.”
The FBI said his method of killing left little obvious signs of a homicide. This meant many of his victims’ bodies were originally not identified, and causes of death were first thought to have been as a result of an overdose, accident or an undetermined cause.
Little’s history of crimes began early, in his teenage years, with what, in comparison to his later crimes, were minor crimes of shoplifting, fraud, breaking and entering and drugs.
But, the FBI said, even then there were “clear signs of a violent streak.”
Little had dropped out of high-school, leaving his Ohio home, and was living a “nomadic life” when his life began taking him along a path of crime.
“He would shoplift and steal in a city or town to gather the money to buy alcohol and drugs, but never stayed in one place for long,” described the FBI. “He would drive from New Jersey to California in a matter of days, reports Palazzolo, and when he had his many run-ins with police, they often just wanted to shoo him out of town.”