Why?

In general, motive can be described as an inward emotion, passion, or feeling in a person which “is likely to lead” that person to do an “appropriate act” as “an outlet” for this emotion. See J. Wigmore, A Treatise on the Anglo-American System of Evidence in Trials at Common Law § 117 (3d ed. 1940) (hereafter cited as Wigmore). The defense particularly contended that the prosecutrix had a feeling of anger towards appellant and a feeling of guilt concerning herself. She argued that it was reasonable to infer that an angry person would do some act of revenge against the person who was the object of her anger. She further intimated that a person experiencing guilt would do some act of revenge against the person who caused this feeling of guilt to surface. The particular acts to be inferred from this emotional state of mind in the prosecutrix were her false accusations that appellant raped her. No argument has been presented by the Government which would lead us to conclude that such acts of revenge could not be reasonably considered appropriate outlets for these emotions. Id.

United States v. Dorsey, 16 M.J. 1, 4 (C.M.A. 1983).