The first cases to be settled among people on the Day of Judgment will be the cases of blood (homicide). [Al-Bukhari]
"«أَوَّلُ مَا يُقْضَى بَيْنَ النَّاسِ يَوْمَ الْقِيَامَةِ فِي الدِّمَاءِ». [صحيح.] - [متفق عليه، واللفظ لمسلم.]"