Investigators in Pennsylvania were today searching for a motive after a 14-year-old schoolboy with no history of disciplinary problems shot dead his headmaster and then turned a gun on himself.

A HEAVILY armed 14-year-old boy shot his school principal inside a crowded school cafe yesterday morning, then killed himself, authorities said.

A heavily armed 14-year-old boy shot and killed his headmaster inside a crowded junior high cafeteria today, then killed himself.