Marino attended Epiphany Apostolic College in Baltimore, Maryland, and later earned his master's degree from St. Joseph's Seminary in Washington, DC.

Marino was ordained a priest for the Josephites at the Basilica of the National Shrine of the Immaculate Conception in Washington, D.C. on June 9, 1962, by Archbishop Philip Hannan.

[1] He was consecrated at the Basilica of the National Shrine of the Immaculate Conception by Cardinal William Baum on September 12, 1974, with Bishops Harold Perry and Edward John Herrmann serving as co-consecrators.

During a talk with these men and women, he stated: Up as a young boy in Mississippi, with the double—I was going to say handicap, but I'll say blessing—of being black and Catholic, I never thought I would see the day when I would be standing here preaching God's holy word in this place, as a priest, indeed as a bishop.

His doctors prescribed rest and seclusion.Marino resigned as archbishop on July 10, 1990, citing the need for "spiritual renewal, psychological therapy and medical supervision".

[2] In August 1990, Vicki Long, a female lay minister, claimed that she and Marino had been engaged in a personal relationship while he was auxiliary bishop in Washington.

[8][2] In 1999, Cardinal John O'Connor honored Marino in a small ceremony at St. Patrick's Cathedral in New York City on the 25th anniversary of his appointment as bishop.