William X. Kienzle was an American author, best known for his crime fiction and mystery novels, particularly the Father Koesler series. He was born in Detroit, Michigan, and ordained as a priest in 1954. Kienzle served as a parish priest for twenty years, during which he also worked as the editor in chief of the Michigan Catholic, the archdiocese’s newspaper. His work with the paper earned him recognition from the Catholic Press Association and the Michigan Knights of Columbus.
In 1974, Kienzle left the priesthood due to his disagreement with the Catholic church's refusal to allow divorcees to re-marry. He moved to Minneapolis and became an editor at MPLS Magazine. It was during this time that he began his prolific writing career, turning out one novel a year featuring his signature character, Father Robert Koesler. Over the course of about twenty years, Kienzle wrote twenty-four novels in the series, with his first, The Rosary Murders, published in 1979 and becoming a huge fan favorite. His books are known for their Detroit, Michigan, settings and their unique blend of crime fiction and Catholic theology.
Kienzle was married to Javan Herman Andrews, a journalist from the Detroit Free Press, from 1974 until his sudden death from a heart attack on December 28, 2001. His biography, Judged by Love, was published in 2003, offering a deeper look into his life and career. Kienzle's work as a priest and his experiences within the Catholic church undoubtedly influenced his writing, providing a unique perspective on crime fiction and mystery novels. His contributions to the genre and his memorable character, Father Koesler, have left a lasting impact on American literature.