The FBI has released the portraits a serial killer drew of his victims in the hope that they can be identified.
Samuel Little, 78, confessed to killing 90 people over three decades last year, while already serving three life sentences for murder.
The killings took place across the US between 1970 and 2005.
Investigators say he targeted "marginalised and vulnerable women", and that some of their bodies went unidentified and deaths uninvestigated.
Having heard all of his confessions, they believe he could be one of the most prolific serial killers in US history.