South Carolina police have revealed that Todd Kohlhepp, the man they arrested after finding a woman chained in a storage container, had confessed to killing six other people.
The confession came a day after Kala Brown, who was found in the container, told police there were four bodies buried on the 100-acre property in the town of Woodruff, with that of her boyfriend Charles Carver.
Ms Brown, 30, and Mr Carver, 32, went missing at the end of August.
Spartanburg County Sheriff Chuck Wright said on Saturday night (local time) that Kohlhepp had admitted to killing four people at a motorcycle shop in 2003 and also led authorities to the site of two more bodies buried on his South Carolina property.
A day after being rescued Ms Brown told local police she had witnessed Kohlhepp shoot Mr Carver.
Police arrested Kohlhepp, 45, a registered sex offender who works as a realtor, on suspicion of kidnapping on Thursday. Officials said Ms Brown and Kohlhepp knew each other and that her abduction was not a random act.
Ms Brown is being treated at a local hospital.
"We're going to let her heal and make sure she's physically and mentally fine," a police spokesman said.
Ms Brown's family said in a statement that she is "having good moments and bad moments" and "needs time to process and begin to cope with the events that have occurred".