Gene Combs, 46, faces 15 years to life in prison when he is sentenced on July 19. The verdict was read this afternoon in Solano County Superior Court.
Garcia, 22, was shot once in the head in the 5000 block of Silverado Drive the evening of Sept. 1, 2008.
The shooter, Henry Don Williams, 33, of Fairfield, was convicted of first-degree murder for Garcia's death in a separate trial on Friday.
Prosecutors contended that Combs and Williams mistook Garcia for a drug dealer who owed Combs money, and that Combs brought the gun that was used to kill Garcia and was present when he was shot.
Garcia was kept alive for several days after the shooting while his family donated several of his organs.