Born in 1929 in Philadelphia, Fr. Graff was ordained a priest in 1955 in Philadelphia. He became a priest of the Diocese of Allentown, Pennsylvania when that diocese was formed in 1961.
Fr. Graff was in the diocese of New Ulm from June 1 to August 4, 1989 to take part in a clinical pastoral education program at Willmar Regional Treatment Center. During the two months Fr. Graff was in the diocese he may have celebrated Mass at parishes within the Diocese of New Ulm while priests were on vacation or otherwise not available.
Fr. Graff was arrested in 2002 for sexual abuse of a minor in Texas. He died in 2002 while awaiting trial.
In August 2018, a Pennsylvania grand jury released a report about sexual abuse allegations against more than 300 priests during a 70-year period. Fr. Graff is included in the report and is noted as having dozens of accusations against him.