He previously held the same position at West Virginia University, but followed head coach John Beilein to Michigan after the 2006–2007 season.

His twin brother Terry Dunn was the head coach at Dartmouth Big Green men's basketball from 2004–05 to 2009–10.

Born in Raleigh, North Carolina, Dunn moved to Washington, D.C., with his family at age 13, then to Fort Dix, New Jersey three years later when his stepfather, a United States Army officer, was assigned there.

Dunn then enrolled at nearby George Mason University in 1978 and graduated in 1981 with a bachelor's degree in health and physical education with a minor in history.

In 2001, he led Penn State to the Big Ten Tournament semi-finals and to a number 7 seed in the NCAA Tournament; Penn State beat number 2 seed, North Carolina, to advance to the Sweet Sixteen for the first time in over half a century.