If his confession proves to be true, his death tally would surpass that of Ted Bundy, who admitted to the rape and murder of 30 women between 1974 and 1978.
He would also eclipse John Wayne Gacy, who sexually assaulted, tortured and killed at least 33 boys and young men between 1972 and 1978.
Investigations are ongoing but since Little's confession, the former ambulance attendant has been linked to 30 unsolved murders, many involving women who were strangled then dumped.
"So far, we don't have any false information coming from him," Ector County District Attorney Bobby Bland said.
"If all of these are confirmed, he'll be the most prolific serial killer, with confirmed killings, in American history.
"People for years have been trying to get a confession out of him and James Holland is the one who finally got him."
Many of the murders Little confessed to bare striking similarities to those of Carol Alford, 41, Audrey Nelson, 35, and Guadalupe Apodaca, 46 — the three women he was originally convicted of killing and sentenced to three terms of life with no parole.
Little bashed, strangled and masturbated over his victims before dumping their bodies in alleyways and abandoned garages.
His latest confessions have enabled investigators to so far close two previously unsolved murders in the state of Georgia, and another two in Louisiana, after he provided details "that only the murderer would have known," according to an internal Louisiana State Police memo.
In Macon, Georgia, the Bibb County Sheriff's Office said in a statemen that Little's confessions led to the closure of two murder cases, one from 1977 and another from 1982.
In the 1982 case, the body of Fredonia Smith was found in the backyard of a Macon home. She had been strangled.
The 1977 victim has never been identified. Her skeletal remains were found at the edge of bushland in a local backyard.
Two Bibb County investigators travelled to Decatur, Texas, to question Little. The sheriff's office says he gave them specific details and information" linking him to both slayings, and Smith's family was notified about the new developments.
Among the Louisiana victims were Dorothy Richard, 59, who was found dead in 1982, and Daisy McGuire, 40, whose body was discovered in 1996. Both had been strangled.
Little also confessed to the killing of Julia Critchfield, who was strangled and thrown off a cliff and into a dirt pit on the north end of Saucier in 1978, Rosie Hill in Marion County, Florida in 1982, and Melissa Thomas — whose body was found in a cemetery in Opelousas, Louisana, in 1996. All three cases had baffled police and cold case detectives who would regularly try to unearth new information which always proved fruitless.
Prosecutors previously said Little preyed on vulnerable women — those who worked as prostitutes or used drugs, and were most likely to go unnoticed or ignored by police.
Investigations into the latest 90 murders are continuing.
- Additional reporting AP
