“If a thief is caught in the act of breaking into a house and is struck and killed in the process, the person who killed the thief is not guilty of murder.
The slayer should have stayed inside the city of refuge until the death of the high priest. But after the death of the high priest, the slayer may return to his own property.
That way you will prevent the death of innocent people in the land the Lord your God is giving you as your special possession. You will not be held responsible for the death of innocent people.
“If the distance to the nearest city of refuge is too far, an enraged avenger might be able to chase down and kill the person who caused the death. Then the slayer would die unfairly, since he had never shown hostility toward the person who died.