Lawrence M. DeFalco, fifth bishop of the Catholic Diocese of Amarillo, was born on August 25, 1915, in McKeesport, Pennsylvania, to Rosario (Ross) and Margret (Desmone) DeFalco. His father was a streetcar-company foreman. While growing up, Lawrence worked for his father during summers as a laborer maintaining the tracks. He entered St. Vincent's College at Latrobe, Pennsylvania, in the fall of 1933. In the deprivation of the Great Depression, the Catholic Diocese of Pittsburgh decided that it could not support all its future priests, and the bishop dropped half of his seminarians, including DeFalco, who went to St. John's Home Mission Seminary in Little Rock, Arkansas, in 1935. He was ordained to the priesthood in June 1942 at St. Andrew's Cathedral in Little Rock. The same month, he received his first assignment, to St. Patrick's Church in Fort Worth. He was appointed vice chancellor of the Diocese of Dallas-Fort Worth in November 1952. He subsequently became associate pastor at Sacred Heart Cathedral in Dallas (January 1953), was sent by Bishop Thomas K. Gorman to study canon law at the Pontifical Gregorian University in Rome (September 1953), and returned in June 1955 to his diocese, where he became secretary of the diocesan marriage tribunal. In September 1955 he became administrator of St. Michael's parish in McKinney, where he commuted from Dallas. In April 1956 he was made the first pastor of Our Lady of Perpetual Help in Dallas. He was named papal chamberlain with the title of monsignor in February 1961. In January 1962 he became rector of St. Patrick Cathedral in Fort Worth. Upon his graduation from Gregorian University he became a licentiate of canon law and a doctor of divinity.
DeFalco was appointed fifth bishop of the Diocese of Amarillo by Pope John XXIII, to succeed John L. Morkovsky, who went to the Diocese of Galveston-Houston. He was consecrated by Bishop Gorman at St. Patrick Co-Cathedral in Fort Worth on May 30, 1963, and installed on June 13, 1963, at Sacred Heart Cathedral. Three months later, he went to Rome for the second session of the Second Vatican Council; he made subsequent visits there until Vatican II concluded in 1965. The documents of Vatican II fitted well with the bishop's attitudes, and he quickly established many consultative bodies in the diocese. These included pastoral councils and senates of priests, of nuns, and of deacons. In 1964 he and the other bishops of Texas collaborated in establishing the Texas Catholic Conference, the legislative and political arm of the Catholic Church in Texas. DeFalco's administration of the diocese began as the local economy was in decline following the post-World War II economic expansion. He canceled plans for further expansion, approved closings of schools and hospitals, and vastly reduced the diocesan debt. Exploratory surgery in July 1979 revealed advanced cancer of the pancreas, and DeFalco submitted his resignation on August 28. He died on September 22, after declaring to members of his family, "I am ready." He was buried in Llano Cemetery, Amarillo.