Pennsylvania state police Saturday arrested an 11-year-old boy and charged him with two murders after he killed his father's girlfriend and her unborn child, a Pittsburgh newspaper reported, dpa reported.
Police said they believed the suspect aimed a shotgun at the back of the 26-year-old woman's head as she slept Friday morning, then caught the school bus along with her seven-year-old daughter and went to school.
He was charged as an adult in the two homicides - the killing of the woman and a homicide involving an unborn child. The baby was expected to be born in March and died of oxygen deprivation, officials said.
The killing took place in New Castle, in western Pennsylvania, 80 kilometres northwest of Pittsburgh.
"This is something that you wouldn't ever think of in your worst nightmare," Lawrence County prosecutor John Bongivengo was quoted as saying. "It's heinous, the whole situation."