Convicted serial killer Todd Kohlhepp claimed in a letter he wrote to a South Carolina newspaper that he killed more than the seven people he was convicted of murdering.
In a letter to the Herald-Journal in Spartanburg, South Carolina, Kohlhepp, 46, said he had tried to tell investigators about his other victims, "but it was blown off."
"Yes there is more than seven," Kohlhepp wrote in the eight-page letter. "I tried to tell investigators and I did tell FBI, but it was blown off. It's not an addition problem, it's an multiplication problem. Leaves the state and leaves the country. Thank you private pilot's license."
Don Wood, chief division counsel with the FBI's Columbia office, told The Associated Press the agency has a pending investigation, but wouldn't comment specifically on what the FBI is doing.
Kohlhepp pleaded guilty in May to 14 charges including seven counts of murder in exchange for serving seven consecutive life sentences with no chance of parole. The prosecutor agreed not to seek the death penalty as part of the deal.
Kohlhepp was arrested in 2016 after Kala Brown, who had gone missing along with her boyfriend, was found chained on his property. Brown later told police she saw Kohlhepp shoot and kill her boyfriend, Charles Carver. Carver's body was later found in a shallow grave on Kohlhepp's property.
In all, the killings took place over more than a decade, as Kohlhepp ran a real estate business. Among his victims were four people killed at a motorcycle shop in 2003.
A Spartanburg County sheriff's investigative report says Kohlhepp "confessed to investigators that he shot and killed" the owner, service manager, mechanic and bookkeeper of Superbike Motorsports, a high-performance motorcycle shop in Chesnee, South Carolina.
The Associated Press contributed to this report.