Sayyiduna Umar (may Allah be pleased with him) said: In deliberate killing, (the case of) a slave, a settlement and a confession, the 'aqilah (paternal kinsmen) are not liable.
This is how he narrated it, from Amir from Umar; from Umar it is munqati' (broken), and what is preserved is that it is the saying of Amir al-Sha'bi himself.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16359