[2] McCarthy joined the North Stars after the draft at the age of 19 and made the team's opening day roster for the 1979–80 NHL season, playing in a 4–1 win over the Hartford Whalers on October 11, 1979.

[8] McCarthy finished the regular season with 36 points, scoring 16 goals and logging 39 penalty minutes.

[9] The North Stars finished 3rd in the Adams Division with a record of 36–38–16 and qualified for the 1980 Stanley Cup playoffs.

In the first round, the North Stars swept the Toronto Maple Leafs in three games with McCarthy scoring 5 points with 2 goals.

In the second round, the North Stars defeated the Montreal Canadiens in 4 games to 3, and during the series, McCarthy had one goal and one assist.

In the semi-finals, the North Stars were eliminated four games to one by the Philadelphia Flyers, with McCarthy scoring 4 points with 2 goals.

His activities resulted in McCarthy receiving a prison sentence of five years and ten months for conspiracy to traffic a truck full of marijuana in 1994.

He started a hockey program at Leavenworth, earning the respect of his fellow inmates and, eventually, a transfer to a prison in Canada to complete the final year of his full sentence.

[19] In August of the following year, McCarthy announced he was taking a head coaching position with HSC Csíkszereda in the Romanian Hockey League but would continue to remain involved with the Express as one of the owners.

[23] McCarthy suffered a dissected aortic aneurysm and died in the hospital following surgery in Chuburna, Yucatán, Mexico, at the age of 61.