The FBI has released portraits serial killer Samuel Little drew of his victims in prison, in the hope the women can be identified by members of the public.

Little last year confessed to 90 murders dating back to the 1970s and
police have matched as many as 34 unsolved murders to his confessions

The drawings have been released in the hope the victims can be identified by the public

The 78-year-old former competitive boxer last year confessed to committing 90 killings in the US since the 1970s.

A mugshot of Samuel Little. Photo: Facebook

Little made the confessions while serving three life sentences after being convicted in 2014 of strangling three women in the late 1980s.

The FBI said the 16 sketched portraits were recently drawn by Little based on his memories of the victims.

The portraits were added to the FBI website this week alongside a map and list of Little’s victims, which have not yet been matched with missing persons or corroborated by authorities.

The FBI have so far been able to confirm 34 of Little’s 90 confessed killings.

Details of the list – including the suspected gender, race, age of the victims, as well as the locations the suspected murders occurred – are based on interviews with the killer, with all but one of the unmatched victims being women.

The FBI says Little chose to kill marginalised and vulnerable women who were often involved in prostitution and addicted to drugs, and who often went unidentified or their deaths were not investigated.

Although Little has only been convicted of three murders, if his confessions prove to be true he would become the worst serial killer in US history.

A map showing where Samuel Little committed his crimes. Illustration: ABC 

Little had a long record of violence before facing court in 2014.

He had been arrested nearly 100 times, yet served less than 10 years in prison before detectives tracked him down at a homeless shelter in Kentucky in 2012.

It was a DNA match that ultimately helped put him permanently behind bars for killings in California in the 1980s.

During his sentencing in 2014, he continued to claim his innocence, interrupting grieving family members with shouts of: “I didn’t do it.”

Little confessed to the 90 further killings last year after FBI investigators set up an interview with the killer following discovery of a case in Texas which they suspected involved Little.

Authorities were able to place Little passing through the area at the time of the killing, and in exchange for a deal which moved him to a different prison, Little agreed to talk to investigators where he confessed to the murders.