After confessing to the murder of an Ohio high schooler on her spring break outside Jacksonville, Florida, in 1980, a jailed serial killer is continuing to talk to detectives investigating other homicides whose clue trails have gone cold, according to authorities. Billy Mansfield’s confession of the killing of 18-year-old Carol Ann Barrett of Zanesville, Ohio, means officials have now confirmed that he has committed at least six murders. He had previously been handed life sentences in five of the killings, four of which were in California and one of which was in Florida, though officials investigating Barrett’s death made clear in a statement on Thursday that those numbers could grow. “Mansfield continues to cooperate with detectives in other jurisdictions regarding additional cold cases,” said the statement from the Jacksonville sheriff’s office. According to authorities, Barrett visited Daytona Beach with seven friends in March 1980. A man barged into the group’s room at the local Treasure Island Motel, ordered them at gunpoint to disrobe, robbed them and threatened to kill them if they resisted, said Project Cold Case, a Jacksonville-based homicide victims’ advocacy group. Project Cold Case said the attacker then grabbed one of Barrett’s friends – saying that would ensure no one called the police on him – but she panicked, and he became irate. Barrett volunteered to go instead of her friend to appease the gunman. She was found dead a day later in a ditch alongside Interstate 95 in Jacksonville, about 90 miles (145km) away, the local sheriff’s office said. A case supervisor at the agency told WJAX in 2017 that Barrett had been fatally shot, “execution” style, and there was no indication she had put up a struggle. For years, the only piece of evidence that investigations had in Barrett’s killing was a sketch of the motel room intruder, based on the recollection of her friends. Then, in 2017, the Jacksonville sheriff’s office said it also had a partial palm print. Mansfield emerged as a suspect in Barrett’s murder in 2022, the sheriff’s office said, without elaborating on why it turned its focus to him. He later confessed that he abducted Barrett from the motel and murdered her, the sheriff’s office said. He was 24 at the time. The Miami Herald, citing the Toronto Sun, reported that Mansfield had spent most of his life in legal turmoil in connection with sex crime charges. He was also charged with killing three women and two teenage girls in Florida and California between 1975 and 1980. He reportedly buried four of their bodies in the back yard of his Florida home before traveling to California, killing the fifth victim and being arrested. Mansfield was convicted of the California murder and was sentenced to life imprisonment. He then pleaded guilty to the four Florida killings to avoid facing the death penalty in that state. He received four more simultaneous life sentences. The Jacksonville sheriff’s office said it would not seek to prosecute Mansfield in connection with Barrett’s murder, opting to leave him to serve his five life sentences. But it noted his cooperation in other unspecified unsolved killings elsewhere from long ago. Meanwhile, Project Cold Case’s founder, Ryan Backmann, said Mansfield’s confession brought a measure of closure to Barrett’s family. “The family in Ohio was still thinking about Carol every single day,” Backman said to WJAX on Thursday. “When someone sees a 44-year-old case solved, that gives them hope. “For some families, it’s just enough to know who it was – and they are not out there harming other people.”