Father Dan was born in 1947, the second of five siblings in Killarney Southwest Ireland. After high school, he went to seminary in Rome, Italy, attending the University of the Lateran while staying at Irish College. Upon completion of the six-year seminary course, he was ordained to priesthood at the Cathedral in his hometown, Killarney, on July 4th, 1971. That October, he arrived in Sacramento and was assigned Associate Pastor at All Hallows Church. After two years, he was assigned to St. Vincent Parish in Vallejo from 1973-78 and then to St. Anthony Parish in Sacramento from 1978-1983. Bishop Francis A. Quinn then appointed him to study at the Pontifical Biblical Institute in Rome, 1983-1987, graduating with the Pontifical Degree-Licentiate in Sacred Scripture.

On returning in the spring of 1987, he was appointed Associate Director of Continuing Education and asked to direct the RENEW process for the Diocese of Sacramento and was assigned as Pastor of St. Anne Parish, an inner-city multi-ethnic parish in South Sacramento from 1991-1994. He was Pastor of St. James Parish in Davis from 1994-2007 and appointed Pastor of St. Joseph Parish in Vacaville in 2007.