The Prophet ﷺ said, "None is killed unjustly, but the first son of Adam will have a part of its burden." Sufyan said, "..a part of its blood because he was the first to establish the tradition of murdering"  

قَالَ النَّبِيُّ ﷺ لَيْسَ مِنْ نَفْسٍ تُقْتَلُ ظُلْمًا إِلاَّ كَانَ عَلَى ابْنِ آدَمَ الأَوَّلِ كِفْلٌ مِنْهَا وَرُبَّمَا قَالَ سُفْيَانُ مِنْ دَمِهَا لأَنَّهُ أَوَّلُ مَنْ سَنَّ الْقَتْلَ أَوَّلاً