Imputation is the attributing of actions to a source: often, imputation involves actions that are criminal.
Imputation takes words or actions and ties them to a person or a cause. An imputation is when you say "He did it!" Imputations are therefore similar to accusations. Often, this word relates to imputations of dirty deeds, especially illegal deeds. "My brother stole the car" is an imputation. "The butler killed the maid" is an imputation. Imputations place blame, usually for something very wrong indeed. This word is often used in legal situations, when imputations are part of testimony.