From Longman Dictionary of Contemporary English(have) somebody’s blood on your hands(have) somebody’s blood on your handsKILLto have caused someone’s death dictators with blood on their hands → blood
Examples from the Corpus
(have) somebody’s blood on your hands• But I already have too much blood on my hands.• Dad with blood on his hands.• He hated to see her with blood on her hands.• I want him to know he has my son's blood on his hands.• Republicans spent eight years trying to prove President Clinton had blood on his hands.• There's blood on my hands, mine or hers I don't know.• There was blood on his hands and I thought he'd had an accident. 