Convicted serial killer Samuel Little is the most prolific murderer in American history, according to a new FBI announcement which suggests he is culpable for 93 deaths.

Authorities state Little, who was convicted in 2014 of three murders and handed three life sentences, has credibly confessed to dozens more unsolved deaths around the United States.

“Law enforcement has been able to verify 50 confessions, with many more pending final confirmation,” the statement reads.

The shocking news comes just over a year after the inmate turned his confessions over to a Texas Ranger and the FBI, alleging he was responsible for dozens of strangulations across America.

Little is believed to have mainly targeted marginalised women, whose bodies were frequently unidentified and whose deaths were not investigated.

His killings span decades, but Little’s detailed and highly specific confessions have enabled authorities to pin him to dozens of murders.

Little has also provided authorities with portraits he says match the appearances of his victims.

Convicted Murderer Named Most Prolific Serial Killer In American History
via FBI / AP

The FBI is now seeking the public’s help to match his confessions with other murders around the nation.

“For many years, Samuel Little believed he would not be caught because he thought no one was accounting for his victims,” Violent Criminal Apprehension Program crime analyst Christina Palazzolo said.

“Even though he is already in prison, the FBI believes it is important to seek justice for each victim—to close every case possible.”

You can access a list of Little’s unmatched confessions here.

Image: Mark Rogers / AP