Sunan an-Nasa'i, Volume 5, Book 45, Hadith 4811 (DarusSalam) ⓘ
It was narrated from 'Amr bin Shu'aib, from his father, from 'Abdullah bin 'Amr, that the Messenger of Allah said: "The blood money for a disbeliever is half the blood money for the believer." (Hassan)
أَخْبَرَنَا أَحْمَدُ بْنُ عَمْرِو بْنِ السَّرْحِ، قَالَ أَنْبَأَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي أُسَامَةُ بْنُ زَيْدٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " عَقْلُ الْكَافِرِ نِصْفُ عَقْلِ الْمُؤْمِنِ " .
also referenced under: Hadith 4807 (Reference) & Book 45, Hadith 102 (In-Book)