The name ‘Samuel Little’ will never be as famous as Ted Bundy, Jeffrey Dahmer or other fabled murders, but he is being touted as the most prolific serial killer in America’s history.

In November, news broke that Little (above right), who is serving life in prison for three murders, opened up about a further 87 murders, spanning 40 years, that he says he committed, leaving FBI agents stunned.

Investigators have now closed 50 of those cases, believing Little to be the culprit, and his detailed recollections have given authorities little reason to doubt the remaining murders.

To help with their investigation, the FBI has now released some of the sketches, asking the public for help in identifying the women.

Drawn by Little himself, the level of detail, after all of these years, is quite something:

TIME reporting below:

The bureau updated on Tuesday information it had posted in November on its website. The update included drawings made recently by admitted serial killer Samuel Little, based on his memories of some of his victims.

An FBI statement says Little targeted “marginalized [sic] and vulnerable women who were often involved in prostitution and addicted to drugs.” The bureau hopes the information will generate tips and clues from the public that could help solve the dozens of unsolved homicides…

The FBI says Little, whom the bureau said “may be among the most prolific serial killers in U.S. history,” has a criminal record dating to 1956. But only recently has he opened up about the long list of killings he has said he committed.

Agents who have interviewed Little say he remembers his victims and the killings in great detail, including where he was and what car he was driving. But he could provide little help on dates, creating a challenge that the FBI hopes Little’s drawings can help surmount.

As things stand, he has ‘only’ been convicted of the three murders that he is already serving life for, which is quite some way behind The Green River Killer, Gary Ridgway, who was convicted of 49 murders and is serving a life sentence in Washington.

In case you have some time to kill, here’s a doccie about Ridgway:

[source:time]