Leopold (D) employed Shellnitz to commit arson on a building in order to collect insurance money. Two sons of a tenant of the building died in the resulting fire. D and Shellnitz were charged with their murders. The evidence showed that the boys had ample time to escape, but either remained of their own volition or were sent back by their father to retrieve some money left behind. D was convicted and appealed; the trial court refused to instruct the jury that a finding of negligence by the victims would preclude conviction.