They wanted to clear the way for Frank Tate, the eventual Olympic gold medalist, who was being heralded as America's next great middleweight.
After agreeing to move up in weight, Nunn boxed Virgil Hill at the Olympic trials in Fort Worth, Texas.
In the second box-off, Hill dropped Nunn and won by a 5-0 decision to make the Olympic team as the U.S. representative in the 165-pound division.
[6] Nunn's next two title defenses were twelve-round majority decision wins over Iran Barkley and Marlon Starling.
[7] After the loss, Nunn moved up a weight division to super middleweight and won the NABF title with a tenth-round stoppage against Randall Yonker.
On September 12, 1992, Nunn won the WBA and lineal super middleweight titles with a controversial twelve-round split decision over Victor Cordoba.
[10] On December 17, 1994, Nunn traveled to Ecuador to fight Frankie Liles in an attempt to regain the lineal and WBA super middleweight titles.
On August 6, 2002, at a hotel in his hometown of Davenport, Iowa, Nunn was arrested after paying an undercover agent $200 for one kilogram of cocaine, which had a street value of $24,000.
During the three-day sentencing hearing, prosecutors called witnesses who testified about Nunn's drug activity dating back to 1993.