Father Selzer was born in St. Louis to Arthur and Helen (Rau) Selzer. He grew up in St. Stephen Protomartyr Parish in south St. Louis. He was ordained to the priesthood on March 18, 1961, at the St. Louis Cathedral by Cardinal Joseph E. Ritter. After ordination, his first assignment was associate pastor of Mary Queen of the Universe Parish in Lemay. In 1963, he was named part-time assistant in the archdiocesan Tribunal Office. He then became associate pastor at Ste. Genevieve du Bois Parish in Warson Woods. He served at Bishop DuBourg High School in south St. Louis from 1961-63.

From 1965-69, he pursued graduate studies in Rome. After returning to the archdiocese, he was appointed as a member of the Commission on Sacred Liturgy and as associate pastor of Holy Family Parish in south St. Louis. The same year, he was appointed to the faculty of Kenrick Seminary in Shrewsbury, remaining on the faculty while serving as associate pastor of St. Ambrose Parish on the Hill in south St. Louis, St. Martin of Tours Parish in Lemay and St. Richard Parish in Creve Coeur.

Father Selzer was named associate pastor of St. William Parish in Woodson Terrace in 1987, and became pastor there in 1995. He remained there until 2002, when he became senior associate pastor at St. Sabina Parish in Florissant. A year later, he became senior associate pastor of St. Alban Roe Parish in Wildwood. From 2004-09, he served as pastor of St. Andrew Parish in Lemay. He retired in 2009 with residence at St. Matthias.

Burial was in Resurrection Cemetery.