A mumin should never kill another mumin unless it is by mistake. Anyone who kills a mumin by mistake should free a mumin slave and pay blood-money to his family unless they forgo it as a sadaqa. If he is from a people who are your enemies and is a mumin, you should free a mumin slave. If he is from a people you have a treaty with, blood money should be paid to his family and you should free a mumin slave. Anyone who cannot find the means should fast two consecutive months. This is a concession from Allah. Allah is All-Knowing, All-Wise.