Dante Martin, 27, is alleged to have orchestrated a hazing ritual called "Crossing Bus C" that led to the November 2011 death of 26-year-old drum major Robert Champion. The ritual is believed to have involved several band members punching Champion and hitting him with drumsticks.
Martin, who is reportedly scheduled to be sentenced on Jan. 9, could face up to 15 years in prison.
Other former members of the band have been implicated in the case. Twelve were initially charged with manslaughter and 10 with felony hazing.
The Florida A&M band, known as the Marching 100, is known for pioneering methods adopted by other bands around the nation.
BREAKING: Former Florida A&M band member convicted of manslaughter in drum major's hazing death.— The Associated Press (@AP) October 31, 2014