CATAWBA COUNTY, N.C. -- A mother and her three children were found dead inside a home outside Charlotte, N.C. early Thursday, and authorities are now searching for their killer.

Investigators have swarmed the area around the house in Catawba County, north of Conover.

Police said a friend of one of the victims called 911 after seeing a man pull the victim into the home about 7 a.m. When officers arrived, they found a mother, her two daughters and her son all dead of gunshot and stab wounds.

Investigators said the father of the children was at work at the time and is not a suspect.

The man believed to be the killer was seen running behind the home after the slaying. Investigators found a gun in the bushes just after noon.

Authorities said they are looking for a man in his late 30s or early 40s, who is about 5 feet 4 inches tall, wearing a blue hooded sweatshirt and blue jeans or sweatpants. They said the man is either Hispanic or of Asian decent.

The man is believed to be in a black or dark blue newer model Toyota Camry. Investigators said he has likely left the immediate area.

The sheriff said he doesn’t believe the attack was random, but that the killer knew the victims.

Several family members have come to the home to grieve, but the names of the victims have not been released.

For several hours after the homicides, four nearby schools were on modified lockdowns, which meant that all exterior doors were locked and there were no outside activities for students. Those schools are Lyle Creek Elementary, Oxford Elementary, River Bend Middle and Bunker Hill High schools.