Federal law distinguishes a bribery scheme from an illegal gratuity based on the order in which the item of value is offered or provided to the public official. Providing something of value to a public official to influence their official acts will constitute bribery, meaning the offer of the item of value preceded the official act.
By contrast, an illegal gratuity is a gift offered or provided to a public official after that public official is already engaged in an official act. The difference could be subtle but important because, in an illegal gratuity scheme, the government does not need to prove that the public official engaged in the official act in order to receive the gratuity. Essentially, the prosecutors must prove that an individual provided the item of value as a result of a public official engaging in some official act.