Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said: If several people together kill a game animal, and all of them are in the state of ihram, then the penalty will be obligatory on each one of them, and each one must pay the full penalty. If the ruling is to offer a sacrificial animal (hady), then each one must offer a hady. If the ruling is to fast, then each one must fast. Its example is that if several people together, by mistake, kill a person, then the expiation for killing, that is, freeing a slave, will be obligatory on each one, or each one must fast for two consecutive months.