The FBI has confirmed that Samuel Little is now considered the most prolific US serial killer in history.
Little, 79, has been serving multiple life sentences in a California prison since 2012 for the murder of three women.
Last year, he confessed to detectives that he had killed 90 other people, mostly women, across the US between 1970 and 2005.
In a news release on Sunday, the FBI confirmed that crime analysts and investigators believe all of Little’s confessions are credible, having verified 50 of the crimes so far.
This means that he is now believed to have killed more people than Gary Ridgway, known as the Green River Killer, who was previously considered the most prolific killer in the US. Ridgway was convicted of 49 murders in 2004, and is currently serving a life sentence at Washington State Penitentiary.
It is believed that most of Little’s victims were people living on the fringes of society, such as sex workers and drug users, meaning their deaths were never investigated by the FBI.
Speaking to NBC News, FBI crime analyst Christie Palazzolo said: “For many years, Samuel Little believed he would not be caught because he thought no one was accounting for his victims.
“Even though he is already in prison, [we] believe it is important to seek justice for each victim – to close every case possible.”