A teenager found slain with her mother and two siblings Thursday had been headed to school with a friend when she decided to go back after her friend mentioned seeing a suspicious man outside the home, authorities said.

When they got back, the man attacked the teen on the porch in front of her friend and pulled the girl inside the home near Conover, 40 miles northwest of Charlotte, a sheriff's deputy said. The friend called authorities around 7 a.m.

Authorities answering the 911 call from the teen motorist said they found the slain 17-year-old girl, her mother, a 20-year-old sister and the 3-year-old brother inside the home, adding they had been either shot or stabbed to death.

Chief Deputy Coy Reid of the Catawba County Sheriff's Office said authorities were still searching for a suspect in his late 30s or 40s Thursday night. A gun had been found in bushes near the home, Reid added.

Reid said the two teens were preparing to head to a local high school when the driver told her friend she had seen a man lurking near some bushes outside the home. The friend asked the motorist to return so she could investigate, Reid said.

According to Reid, the teen driver told authorities that her friend got out of the car and was unexpectedly met at the front door by the unidentified man, who attacked her and pulled her inside. The other teen who remained in the car was unhurt, Reid said, adding the woman's husband was at a work at the time.

Authorities declined to release the names of the dead, but neighbors have said they were told the victim was Lisa Tzeo and her three children. Property records indicate the home is owned by Brian and Lisa Tzeo.

Jeff Hartman, who lives on the street, said he heard screaming Thursday morning and sirens soon afterward.

"I was half asleep," Hartman said. "I didn't think anything of it until we heard the sirens."

He said the family seemed happy, but mostly kept to themselves.

Nearby schools were put on lockdown Thursday morning while searchers combed the area, but the order was lifted later in the day, officials said.