Hill v. Walker 

Change in law permitting parole hearings to be scheduled less frequently than once a year is not ex post facto law, as law provides that Parole Board can consider inmate's petition for more frequent parole hearings, and can conduct hearings less frequently that annually only upon express finding that it would not reasonably expect parole to be granted any earlier. Change in the way Illinois Prisoner Review Board has interpreted statutory criteria for parole, "seriousness of offense", does not violate ex post facto principles or separation of powers principles, because Board is granted very broad discretion and how it is exercised may change over time; and no claim that new rule or new statute has been implemented, or that Board is without discretion.