A Duval County jury convicted Lucious Jackson in the 2010 murder of former Marine Gregory Chisholm.
Chisholm was filling up his car at a Northside BP gas station in April 2010 when someone tried to rob him, police said. Chisholm fought back and was shot and killed.
Police said Jackson admitted to two people that he had been out pulling robberies that night. In each case, he said Chisholm tried to get the gun away from him, according to police, and he fired one shot and fled, not knowing if he killed Chisholm.
Attorneys said Chisholm threw some loose change in Jackson's face before he was shot.
Jackson faces life in prison at his sentencing.