Barnes has been in prison since the August 2007 death of Philadelphia police Officer Walter Barclay, whom Barnes shot and paralyzed in a botched burglary 41 years earlier.
He was charged with murder after Barclay's death and was found not guilty, but he remains imprisoned on parole violations.
Defense lawyer Sam Silver says Barnes has served nearly three years of additional prison time for driving and for having a cell phone without his parole officer's permission.
Silver also says it makes no sense to deny parole based on his elderly client's prison escape attempts from the 1980s. He says his client is rehabilitated and has been a model prisoner.