The Prophet [SAW] said: "No person is killed wrongfully, but a share of responsibility for his blood will be upon the first son of Adam, because he was the first one to set the precedence, of killing." (Using translation from Nasāʾī 3985)
عَنِ النَّبِيِّ ﷺ قَالَ لَا تُقْتَلُ نَفْسٌ ظُلْمًا إِلَّا كَانَ عَلَى ابْنِ آدَمَ كِفْلٌ مِنْ دَمِهَا ذَاكَ أَنَّهُ أَوَّلُ مَنْ سَنَّ الْقَتْلَ