Griffin admitted to jurors that he killed Belton in December 2009 by stabbing him 22 times with a knife that had a 10-inch-long, double-edged blade.
Griffin had claimed Belton, an assistant English professor, raped him on Dec. 25, 2009, after a day of heavy drinking at Belton’s Bloomington home.
He said he killed Belton two days later in a rage when he confronted him about the alleged assault.
The verdict came after 12 hours of deliberations. Griffin, now 27, faces a maximum sentence of 65 years.