GAFFNEY, S.C. (AP) - A terrified rural South Carolina community hunkered down over the Fourth of July after the sheriff said a serial killer was on the loose, and longtime residents were reminded of a murderer who terrorized the town in the 1960s.

Memories of the "Gaffney Strangler" were reignited this week after authorities said a new serial killer gunned down four people during three separate incidents over several days. Authorities have released a sketch of the accused killer and a description of the sport utility vehicle he may be driving, but they have been silent about exactly what has linked the slayings.

The town of Gaffney, about 50 miles south of Charlotte, N.C., is located in a county that had just six homicides in all of 2008, and half that the year before. The last time the town was this threatened like this was when the "Gaffney Strangler" killed four women over 10 days in 1968 and vowed to kill more. The town banded together, despite racial prejudice, to find the man who was killing both white and black women.

The strangler, Lee Roy Martin, called the editor of a local newspaper on Feb. 8, 1968, and told him where to find the bodies of two women he'd dumped in the woods. He threatened to kill even more women until he was "shot down like the dog I am."

People started to comb the community for clues, which led to Martin's arrest. He was convicted of four murders and sentenced to four life terms. In 1972, he was stabbed to death in his cell.

The latest killings have residents on edge, with "their guard up and their gun handy," said state Sen. Harvey Peeler, R-Gaffney.

"There is no greater fear than the fear of the unknown and nobody knows. You can cut the tension with a knife," Peeler said. "People are locking their doors, even in broad daylight."

Tanya Phillips had been looking forward to a backyard barbecue at her brother's house but instead planned to stay home with her doors locked.

"I'm not taking any chances," said Phillips, 32, a mother of two who works in a day-care center. "I'll go out during the day, but not at night. I just don't feel safe."

Every available police officer will work the weekend, Cherokee County Sheriff Bill Blanton said, acknowledging there is "real fear in the county." He urged people to take precautions such as going out in groups and calling 911 if their cars break down and they are stuck on the side of the road.

The latest victims were found in their family's small furniture and appliance shop near downtown Gaffney around closing time Thursday. Stephen Tyler, 45, was killed, and his 15-year-old daughter was shot and seriously injured. Family members and a store employee found them in the Tyler Home Center.

A day earlier and about seven miles away, family members found the bodies of 83-year-old Hazel Linder and her 50-year-old daughter, Gena Linder Parker, bound and shot in Linder's home. Blanton would not say if Tyler and his daughter were also bound.

The killing spree began last Saturday about 10 miles from Tyler Home Center, where peach farmer Kline Cash, 63, was found shot in his living room. Blanton said the killer may have first spoken with Cash's wife about buying hay. She left and came home a few hours later to find her husband's body. Investigators said it appears he was robbed, but they have not determined if anything was taken in the other killings.

Hazel Smith, 47, said neighbors feel vulnerable.

"If he killed once, he'll kill again," she said sitting on the front porch with her friends. "Tonight, I'm going to stay inside and pray, pray a little harder that he gets caught."

The latest shootings happened less than a half-mile from the sheriff's office, where at least 30 investigators were already working on the case. Blanton said a profiler has suggested Tyler and his daughter might have been shot to taunt investigators, but he said his only concern is solving the case.

"We had a 15-year-old girl shot; he killed an 83-year-old woman," Blanton said. "The good people of this community don't deserve that."

Associated Press writers Jim Davenport and Jeffrey Collins contributed to this report from Columbia.