Mont. Code Ann. § 45-2-302
A person is legally accountable for the conduct of another when:
(3) either before or during the commission of an offense with the purpose to promote or facilitate the commission, the person solicits, aids, abets, agrees, or attempts to aid the other person in the planning or commission of the offense. However, a person is not accountable if:
(b) before the commission of the offense, the person terminates the person's effort to promote or facilitate the commission and does one of the following:
History: En. 94-2-107 by Sec. 1, Ch. 513, L. 1973; R.C.M. 1947, 94-2-107; amd. Sec. 1640, Ch. 56, L. 2009.