It is reported about Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he said, regarding a person who commits offences liable to the prescribed punishments (hudud) and is then killed deliberately, Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: When killing comes, everything (that is, every sin) is wiped out.
Al-Tabarani recorded it; its chain contains a narrator who is not named, and the rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحدود والديات / 10603