HAMMOND, Ind. (AP) _ Authorities might seek the death penalty against a man accused of fatally stabbing his girlfriend, their two children and her mother, and then setting their house on fire.

''A death penalty count is certainly a possibility with a multiple killing like this,'' said Lake County Prosecutor Jack Crawford.

Dennis Roarke, 25, was charged Friday with four preliminary counts of murder and was being held without bond.

Cpl. Steve Ridgley noticed the fire about 6:30 a.m. and tried to enter the home but was driven back by heat and smoke.

The bodies were found in the living room after the fire, police said.

Autopsies determined the victims died from stab wounds, said Lt. Robert Seaman.

The victims were identified as Mary Elizabeth Waggoner, 19; her two children, 18-month-old Dennis and 3-month-old Mary Ella; and her mother, Betty J. Waggoner, 61.

Police said Roarke was hitchhiking in Gary when he was offered a ride by a truck driver, who told police the man was covered with blood and had told him he stabbed four people and set fire to their house.