Musnad Abu Ya'la al-Mawsili 152:111

And from al-A'mash, from 'Abdullah ibn Murrah al-Hamdani, from Masruq, from 'Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no soul that is killed unjustly, except that there is upon the son of the first Adam a portion of its blood, because he was the first to establish killing."