[3] Prior to joining the Bruins, Mooney worked in the horse racing industry.
[3] During his tenure as president, he twice reached agreements with the Boston Celtics to remain at the Garden,[8][9] led the effort against the NHL–WHA merger,[10][11] worked on the Bruins' failed move to Salem, New Hampshire,[4][12] fired longtime Garden organist John Kiley,[13] and along with other members of Bruins management helped take care of Bruins' player Normand Leveille after he suffered a cerebral hemorrhage and fell into a coma.
While working for the Bruins and the Garden, Mooney also owned part of the Campbell Sports Network, a Plymouth, Massachusetts-based radio network than owned the rights to Boston Red Sox games from 1983 to 1989.
He was credited by sportswriter Will McDonough with helping bring the Boston Marathon back to prominence.
[17] Mooney died on April 23, 2000, at the age of 59 at his home in Duxbury, Massachusetts, due to cancer.