The local archbishop expressed his conviction during the homily that the missionary is both a martyr and a saint.
Fr. Rother spent 13 years in Guatemala as a parish priest in Santiago Atitlan, a small town caught up in the country's civil war in the 1970s and 80s.
Aware that his life was in danger he returned to Oklahoma in Jan. 1981, but went back to Guatemala months later after recognizing that his heart was with the people.
He was assassinated on July 28, 1981 by three men who broke into the mission rectory.
Fr. Rother's cause for canonization was initiated in Oct. 2006 when Archbishop of Oklahoma City, Most Rev. Eusebius J. Beltran, commissioned a committee to collect information about his life and the circumstances that led to his death.
He also contracted a canon lawyer, Dr. Andrea Ambrosi, to act as postulator in Rome.
Ambrosi's law firm specializes in causes for beatification and canonization. Incidentally, they are also managing the cause of Cardinal John Henry Newman, who will be beatified by the Pope on Sept. 19.
Extensive documentation has been compiled on the life and service of the Oklahoma priest which has been verified by an archdiocesan tribunal. Just this week, it was consigned to Ambrosi, thus beginning the "Roman phase" of the cause.
During Tuesday's Mass, Archbishop Beltran remembered Fr. Rother as a country priest sent on mission to Guatemala, where "he served faithfully and zealously, bringing the Good News of Jesus to the poor in a simple but powerful manner.
"Totally dedicated to God and to his people, Father Rother preached the Gospel with love and conviction. It was this faithful teaching and living the Word of God which made him a target of hatred and evil," said the archbishop.
Citing a "spontaneous outpouring of prayer and devotion," in Guatemala and in the U.S. since his death, Archbishop Beltran said, "We believe and we are convinced that Father Rother was martyred and is now a saint in heaven."
To make beatification possible, the postulator must now prove to the Vatican congregation for saints that Fr. Rother was killed solely for his faith, that his death was violent and that he accepted such a death for the faith.
SIC: CNA