Duca was ordained a priest by Bishop Thomas Tschoepe for the Diocese of Dallas at St. Thomas Aquinas Church on April 29, 1978, in Dallas.[3] After his 1978 ordination, the diocese assigned Duca to pastoral roles at the following Texas parishes:
Duca was appointed as bishop of Shreveport by Pope Benedict XVI on April 1 2008.[4] He was consecrated by Archbishop Alfred Hughes on May 19, 2008, at the Shreveport Convention Center, with approximately 3,000 people in attendance. Archbishop Michael Sheehan and Bishop Kevin Farrell were the co-consecrators.[3] Duca was one of the regular panelists on the American Religious Townhall television program.
Bishop of Baton Rouge
Duca was appointed on June 26, 2018, by Pope Francis as the sixth bishop of Baton Rouge, succeeding Bishop Robert Muench, who retired. Duca was installed by Hughes on August 24, 2018.[5][3]