Hadith 1540Q5

Imam Malik, may Allah have mercy on him, said that if several people together kill one person in such a way that he dies immediately from the blows of all of them, then all of them will be killed in retaliation (qisas). And if he dies after several days, then qasamah will become obligatory. In this case, due to qasamah, only one person among them will be killed, because through qasamah only one person is always killed.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب القسامة / 1540Q5
Hadith Takhrij «فواد عبدالباقي نمبر: 44 - كِتَابُ الْقَسَامَةِ-ح: 2ق4»