The Illinois Supreme Court has decided not to hear the case of Jamie Snow.
He is a Bloomington man serving a life sentence for murdering a gas station attendant in 1991 during an armed robbery.
He was convicted in 2001.
His supporters say there is evidence that points toward his innocence, including conflicting testimony from Jeff Pelo, the first officer on scene, as well as other statements from witnesses who have since retracted or changed their stance.
They also say physical evidence from the scene should be tested with new technology.
Snow's appeals have now been rejected at every level within the state.