Sometimes the absence of a thing is a vital clue. For example, the absence of fingerprints on an often-used item makes it clear that the item was cleaned. A tool missing from a set could well be the murder weapon. Can lead to a Conviction by Contradiction situation if poorly handled. Compare I Never Said It Was Poison, where someone incriminates themselves by mentioning details which were withheld from the public. Examples of Absence of Evidence include: