Over the past decade, Unger has ministered to prisoners on death row and given presentations to high school students about how to avoid making bad choices in life.
At his parole hearing two weeks ago, Humble admitted to killing Rodrigue after getting in a fight, though he blamed Rodrigue for killing both of the cab drivers. A 2015 ruling clarified that the initial decision applied retroactively to people already in prison.
The case that spurred the 2015 decision was brought by a Louisiana inmate, Henry Montgomery, who as a teenager was convicted of murdering an East Baton Rouge sheriff's deputy.
The justices decided Montgomery, now in his 70s, deserved access to parole, despite a Louisiana law banning it.
In the past month, Louisiana's parole board has heard three such cases, including Unger's.
Two of them involved killings in the New Orleans area.