Willard Richards notifies the Church in Times and Seasons of the excommunication of William Smith on Oct 12, 1845 for having "turned away from the truth".
Willard Richards, "Notice," Times and Seasons 6, no. 16 (November 1, 1845): 1019
Elder William Smith having been cut off from the Quorum of the Twelve for apostacy, on the Sunday following, several letters & a pamphlet having been read, showing he had turned away from the truth; on motion, it was unanimously resolved by the church of Jesus Christ of Latter-day Saints, the the said William Smith be cut off from said church, and left in the hands of God.
W. Richards, Cl'k.
Nauvoo, Oct. 12, 1845.