Add a rule to the ruleset, entitled Forensic Investigation:

As a Daily Action, any Amnesiac with at least 5 Evidence can Interrogate the Evidence by reducing their Evidence by 5 and sending a private message to the Past Memory to that effect, including the name of a single Role. The Past Memory should then, at their first opportunity, respond with the names of three Amnesiacs, with one being chosen because they have the named role and the other two being selected at random. If no Amnesiacs have the named role then the Past memory should name three Amnesiacs at random.