Justin M. Wachs, Sr., J.C.D., was ordained a Catholic priest for the Diocese of Sioux Falls on June 11, 2004. During his service in the Diocese, he served as a pastor to the Hispanic Community in the city of Sioux Falls, secretary to the Bishop of Sioux Falls, Moderator of Curia, Defender of the Bond, Promoter of Justice, Delegate for Discipleship and Evangelization, and Master of Ceremonies. In 2009, he received certification in medical ethics from the Medical Ethics Certification Program of the National Catholic Bioethics Center. He earned his license and doctorate in canon law at the Pontifical Gregorian University in Rome in 2012 and 2013. In 2015, he was called into service at the Holy See in the discipline section of the Congregation for the Doctrine of the Faith. In 2017, he left active priestly ministry, seeking a dispensation from the obligations of the clerical state, and entered into private practice as a canon lawyer, canonical consultant, and advocate.

His varied pastoral ministry provided him with a wide variety of professional experience in canon law at diocesan and universal levels: diocesan administration, liturgical and penal law, and temporal goods. He assisted with the civil and canonical restructuring of the Diocese of Sioux Falls. His work in the service of the Holy See provided him with vast experience in the reserved delicts, in particular, cases of accusations against clerics. He has experience in advocacy for priests as well as in marriage cases. He is a member of the Canon Law Society of America. He has authored articles in canon law and his dissertation was published under the titleObsequiumin the church: sacred tradition, Second Vatican Council, 1983 Code, and sacred liturgy.