Ensign, July 1999, pg. 65; “Excommunication: Ordinance work for deceased persons who were excommunicated at the time of their death requires First Presidency approval. For more information, contact Special Services…
Questions of worthiness: Temple ordinances may be performed for deceased persons one year or more after the date of death without regard to worthiness or cause of death. This includes those who may have taken their own lives or the lives of others.
As you provide ordinances for your ancestors, do not try to determine their worthiness, whether they will accept the ordinances, or the feelings of other deceased persons affected by the ordinances. In order for these ordinances to be binding in eternity, they must be sealed by the Holy Spirit of Promise, and the people involved must merit them by their individual worthiness and accept them. These determinations must be made beyond the veil.”
Hebrews 9:12; “Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.”
The reference above will not be found in the Ensign article listed. The Ensign article lists the guidelines for the Endowment Ceremonies performed in the LDS temple. The reference about the excommunicated members and thereafter is at the end of the list that was not published in the Ensign. There are no other published works of this guideline except for what we found on the web which you can access here,