The killings have taken place in or around the small town of Gaffney. For some residents, the recent events are a reminder of the "Gaffney Strangler", who terrorised the community in the late 1960s.
The strangler, Lee Roy Martin, killed four women over 10 days in 1968 and vowed to kill more, before being arrested.
Fear and concern
Police have released a sketch of a male who is said to be tall with salt and pepper hair.
"We're knee-deep in the investigation," said County Sheriff Bill Blanton.
"There's fear and concern here and there should be concern."
He would not say how the five deaths were related but it is known that all victims were shot:
• Abby Tyler died on Saturday after being wounded on Thursday as she worked with her father in an appliances store in Gaffney; Stephen Tyler, 45, was found dead at the scene
• Relatives found Hazel Linder, 83, and her daughter Gena Linder, 50, bound and shot to death in their home on Wednesday, seven miles from the scene of the Tyler shootings
• Peach farmer Kline Cash, 63, was found dead in his home by his wife on Saturday (27 June)
The shootings all occurred within about 10 miles (16km) of each other in Cherokee County, a rural community of 54,000 people set amid peach orchards and farms some 50 miles west of Charlotte, North Carolina.
Dozens of local, state and federal investigators have been assigned to the case.
Cherokee County resident Hazel Smith, 47, told the Associated Press news agency her neighbours felt vulnerable.
"If he killed once, he'll kill again," she said.
"Tonight, I'm going to stay inside and pray, pray a little harder that he gets caught."
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