When Allah granted His Messenger the conquest of Mecca, the Prophet ﷺ stood among the people, praised Allah and glorified Him, then said, "Whoever has had a relative killed has the choice between two options, either to pardon, or to have the killer executed."
حدثنا محمود بن غيلان ويحيى بن موسى قالا حدثنا الوليد بن مسلم حدثنا الأوزاعي حدثني يحيى بن أبي كثير حدثني أبو سلمة
لما فتح الله على رسوله مكة قام في الناس فحمد الله وأثنى عليه ثم قال ومن قتل له قتيل فهو بخير النظرين إما أن يعفو وإما أن يقتل
Agreed upon [by Bukhari and Muslim]. Bukhari narrated it in the Book of Lost Property, chapter on how the lost property of the people of Makkah is identified, hadith no. 2434, from Yahya bin Musa, and Muslim, hadith no. 1355, from the hadith of Walid, with the same wording.On this topic, there is also a narration from Waail bin Hajar [Muslim: 1680], from Anas [Ibn Majah, hadith no. 2691], and from Abu Shurayh Khuwaylid bin Amr [to come: 1406].