PROVIDENCE, R.I. (AP) – The American Civil Liberties Union has sued the Rhode Island Department of Corrections over the continued imprisonment of an inmate who was granted parole.

The Providence Journal reports that Robert McKinney was sentenced in June 1997 to life in prison for murder and a consecutive sentence of 10 years for conspiracy.

The ACLU says under Rhode Island law, an inmate who is serving consecutive sentences is eligible for parole after serving one-third of the total sentence.

The Parole Board voted unanimously to grant parole on May 16, with a release date of December 2019.

However, the Department of Corrections changed how parole eligibility is calculated with out notifying McKinney or the parole board.