GAFFNEY, S.C. — 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'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."

Plenty of evidence links the killings, though officials have not yet determined how the victims are connected or if they knew whoever shot them, 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.

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 in Tyler Home Center, 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. Blanton would not say if Tyler and his daughter were also bound.