Police in Tempe, Arizona are searching through unsolved murder cases from the last 30 years to see if there are any connections to alleged South Carolina serial killer Todd Kohlhepp.

The 45-year-old real estate agent was charged with kidnapping and murder after a woman was found chained inside a storage container on his property on 3 November, 2016.

According to WLTX19, a Spartanburg County sheriff's deputy reportedly told Melissa Ponder Brackman that investigators had arrested Kohlhepp in connection to the 2003 shooting of her husband, business owner Scott Ponder. During the call, the deputy told Brackman that Kohlhepp "admitted to shooting somebody in Arizona."

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"There isn't a specific case that we're looking at directly, but they are working on it and it just takes a little bit of time," Tempe Police Department Detective Lily Duran said.

Sgt Josie Montenegro, public information officer with the police department, told GoUpstate.com that the agency would be looking at a specific window of time between August 2001, when Kohlhepp was released from a 15-year prison sentence for kidnapping, and approximately November 2001, when he returned to South Carolina.

Investigators will also go back to 1986, when Kohlhepp was originally arrested for kidnapping a 14-year-old girl at gunpoint and sexually assaulting her. He was 15 at the time.

Spartanburg County Sheriff Chuck Wright said Kohlhepp has confessed to killing seven people in South Carolina.

Kohlhepp was arrested after 30-year-old Kala Brown was found alive and chained in a storage container. Kohlhepp was charged with kidnapping and four counts of murder after telling authorities he killed four at Superbike Motorsports in Chesnee, South Carolina.

WLTX19 reported that Brackman and relatives of three other victims killed at the motorcycle shop are preparing to file a wrongful death lawsuit against Kohlhepp. Attorney Doug Brannon said, "I believe these families are entitled to anything they can get."

The bodies of Brown's boyfriend, Charlie Carver, and missing Spartanburg couple, Meagan McCraw Coxie and Johnny Coxie were also found on Kohlhepp's property. However, charges have not yet been filed for those deaths.