After shooting his father with the arrow, Christopher Krumm stabbed himself, then fatally stabbed his father in the chest in a struggle in the classroom, Walsh said.
Police began getting reports about the attack on Arnold and soon after they responded by the dozen to the campus attack. Authorities locked down the campus for two hours while they scoured the grounds for any other attackers. They were reassured that Christopher Krumm acted alone.
He had smuggled the compound bow - a type much more powerful and effective for hunting than a simple, wooden bow - onto campus beneath a blanket, Walsh said.
He said Christopher Krumm also had two knives with him, and the knife used was "very large."
Arnold's body was found in the gutter of her street, and evidence suggested much of the attack occurred outside the home, Walsh said.
