BARSTOW, Calif: A pack of pit bulls surrounded a woman and mauled her to death, authorities said Wednesday.

Police found Kelly Caldwell, 45, lying in the street around 9:30 p.m. Tuesday, and took her to a hospital, where she later died, the San Bernardino County sheriff's department said.

After the mauling, the dogs ran to a nearby house. Deputies shot one dog to death when it returned to the scene and acted aggressively as paramedics were trying to save Caldwell's life, authorities said.

A second dog was shot to death Wednesday morning when it, too, returned. Deputies said it became aggressive as an animal control officer tried to capture it.

Authorities said at least one dog belonged to a neighbor.

Investigators collected DNA samples from the dogs. An autopsy will be performed on Caldwell and necropsies on the dogs to determine which one attacked Caldwell, sheriff's Sgt. Richard Ells said.

Detectives also are looking into whether the dogs' owners knew whether the animals had any history of violence. If the dogs were dangerous and the owners knew it, they could face criminal charges, Ells said.