FBI releases serial killer's drawings in a bid to identify his victims
The FBI has released a series of portraits that serial killer Samuel Little drew of his victims in the hope that they can be identified.
The 78-year-old confessed to killing 90 people and is already serving three life sentences for murder.
It is believed that the killings of "marginalised and vulnerable" women took place across the US between 1970 and 2005.
He could be one of the most prolific serial killers in US history - however many of his victims remain unknown.
Now the agency has released 16 images, which were drawn from memory, in the hope that they can find out more information and notify families.
An FBI spokesman told CNN: "We are hoping that someone - family member, former neighbour, friend - might recognise the victim and provide that crucial clue in helping authorities make an identification.
"We want to give these women their names back and their family some long awaited answers. It's the least we can do."
Little was caught after being arrested on a drugs charge in a homeless shelter in Kentucky, and extradited to California in 2012.
DNA testing linked him to three murders in the Los Angeles area dating back as far as 1987. All three women had been beaten and strangled.
He was accused of murdering women in Mississippi and Florida in the early 1980s but was not convicted.
More recently he began drawing portraits of his victims during interviews with investigators.
The drawings include details such as the color of a victim's eyes or hair or the blue headscarf she was wearing when she was abducted.
One picture, for example, depicts a white woman with green eyes and brown hair aged between 20 and 25 years old who was killed in Maryland in 1972.
Another is of a black woman between 23 and 25 years old with bright red lipstick and red earrings. She was killed in 1984 in Georgia and may have been a college student.
Another is of a black woman with purple hair aged between 25 and 28 years old who was killed in Houston, Texas, decades ago.
Bobby Bland, the district attorney in Ector County, Texas, told AFP in December that the total number of confirmed killings attributed to Little is now more than 40.
"He's talking about things, cases that happened up to 50 years ago, and he's giving details on all these different murders, and none of the statements he's made have proven to be false," Bland said.
The FBI has been working with federal, state and local agencies to match Little's confessions to unsolved murders across the country.
If all 90 confessions are confirmed, Little would be the most prolific known US serial killer.
The deadliest known US serial killer is believed to be Gary Ridgway, the so-called "Green River Killer" convicted of 49 murders who is serving a life sentence in Washington state.