The Prophet ﷺ said, "The first cases to be decided among the people (on the Day of Resurrection) will be those of blood-shed." (Using translation from Bukhārī 6864)
عَنِ النَّبِيِّ ﷺ قَالَ «أَوَّلُ مَا يُقْضَى بَيْنَ النَّاسِ فِيهِ يَوْمَ الْقِيَامَةِ فِي الدِّمَاءِ»