Ohio Department of Rehabilitation and Correction, File, Associated Press
FILE- This undated file photo provided by the Ohio Department of Rehabilitation and Correction shows Arthur Tyler. Cuyahoga County Prosecutor Tim McGinty planned Monday, April 21, 2014, to submit his position on whether condemned killer Tyler, who is facing execution next month for a Cleveland produce vendor’s 1983 slaying, should receive mercy. Attorneys for defendant Tyler say he should receive clemency partly because a second defendant repeatedly admitted being the shooter.

COLUMBUS, Ohio — A lawyer for a condemned Ohio killer set to die next month says he should be spared because of grave doubts about his guilt.

Public defender Vicki Werneke says clemency is the only way to address the fact that defendant Arthur Tyler is on death row while his co-defendant, who took responsibility for the fatal shooting of a Cleveland produce vendor in 1983, is now out of prison.

Werneke also told the Ohio Parole Board Thursday that the court system has been unfair to Tyler throughout his prosecution.

Attorneys representing Tyler made arguments to the Ohio Parole Board Thursday, to be followed by Cuyahoga (ky-uh-HOH'-guh) County prosecutors.

In a rare move, prosecutors will argue Tyler's sentence should be commuted to life without parole because of questions about the conviction.