Federal Bureau of Investigation releases drawings by United States serial killer to identify victims

The FBI released these portraits drawn by confessed serial killer Samuel Little a man who claims he's murdered more than 90 people. He claims the portraits are of his victims.

The FBI released these portraits drawn by confessed serial killer Samuel Little a man who claims he's murdered more than 90 people. He claims the portraits are of his victims."We are hoping that someone- family member former neighbor friend

Little is serving three consecutive life sentences with no possibility of parole. But starting last May, Little shared story upon story of the dozens of other vulnerable women - many of whom were involved in prostitution and addicted to drugs - who he claimed to have strangled to death, leaving a trail of bodies across the country.

He could be one of the most prolific serial killers in United States history - however many of his victims remain unknown.

Investigators encouraged him to do so, and using a mix of chalk, pastel pencils and watercolours he has drawn 16 in their final frightened moments, the last known images of the victims until police found their remains.

The bureau told CNN they hoped "someone - family member, former neighbor, friend - might recognize the [victims] and provide the crucial clue in helping authorities make an identification".

He gave each a unique feature or two: A Miami teenager's blue headband holds back long black hair; a victim in Atlanta has sharp features and appears caught in mid-laugh; and a woman slain in Texas has purple hair.

Samuel Little, 78, sparked investigations into cold cases in several USA states after he began confessing to the crimes last May.

Little was caught after being arrested on a drugs charge in a homeless shelter in Kentucky, and extradited to California in 2012.

This undated file photo provided by the Ector County Texas Sheriff's Office shows Samuel Little.

He was accused of murdering women in MS and Florida in the early 1980s but was not convicted.

He remembered where he was, what auto he was driving and could even draw pictures of the women he killed, the Federal Bureau of Investigation said. All of the women have bright and plump, red lips. She was killed in 1984 in Georgia and may have been a college student.

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 has released sketches and other information on a string of unsolved cold-case homicides that investigators say a serial killer admitted to carrying out.

"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", Mr Bland said.

The stunning confessions could make Little the most prolific serial killer in USA history if these cases are confirmed by law enforcement, Ector County District Attorney Bobby Bland told CNN in December.

The deadliest known USA 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.