He used a .22-calibre pistol to fire 10 shots at a group of students in Chardon High School's cafeteria, killing 16-year-olds Daniel Parmertor and Demetrius Hewlin, and Russell King, 17.
Mr Evans and Mr McGrath were each charged with the unlawful possession of a 9mm calibre Beretta semi-automatic pistol and seven rounds of ammunition with intent to endanger life.