The Ohio Parole Board heard Arthur Tyler’s appeal for clemency Thursday in a case notable for the fact that Cuyahoga County Prosecutor Timothy J. McGinty also believes Tyler should not have to die for a 1983 Cleveland murder in which his co-defendant — who’d originally admitted to firing the shot that killed elderly vegetable seller Sander Leach but later changed his story and testified against Tyler in a plea deal — now walks free after serving 20 years.