Section One of the Upāsaka Precepts Sutra on the Five Precepts, Original Text:
If one dispatches someone to die on the road: knowing that there are ferocious beasts hungry on that road, one dispatches the person one wishes to kill to that perilous road. With this thought: "Let him die on that perilous road." If that person dies, the upāsaka commits an unpardonable offense. Others also commit offenses. The rest is as stated above. This is called killing on a perilous road.
Explanation: The method of killing by dispatching someone to die midway is as follows: The upāsaka, knowing beforehand that there are ferocious beasts hungry on that road, dispatches the person he wishes to kill to that perilous road, thinking thus: "Let him die on that perilous road." If that person dies, the upāsaka commits an unpardonable offense. If that person does not die immediately but later dies as a result, the upāsaka also commits an unpardonable offense. If that person does not die immediately and later does not die as a result, the upāsaka commits a medium pardonable offense. This is the method of killing on a perilous road.
Although the person was eaten and killed by the beast, not directly by the upāsaka's own hand, because it was caused by the upāsaka's deliberate design, it is equivalent to the upāsaka killing him. This is even more serious than killing with one's own hand, as it unjustly causes the beast and that person to form an evil karmic bond. In the future, when the beast repays this debt, it will be far more grievous than a life for a life.