GAFFNEY, S.C. (AP) - Terrified residents canceled Fourth of July plans and holed up in their homes Friday as investigators hunted a serial killer believed to have shot four people to death.

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'll go out during the day, but not at night. I just don't feel safe," said Phillips, 32.

Plenty of evidence links the killings, though officials have not yet determined how the victims are connected or if they knew the shooter, said Cherokee County Sheriff Bill Blanton.

"Yes, we have a serial killer," he said at a news conference in this rural community 50 miles south of Charlotte, N.C.

So far, all investigators have to go on is a sketch of a suspect and a description of a possible getaway vehicle, though police would not say who provided that information.

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. Tyler's wife, his older daughter and an employee found them, County Coroner Dennis Fowler said.

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.

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.