NEW HAVEN, Conn. — A Connecticut man already serving a 45-year prison sentence on a felony murder conviction has pleaded guilty to an unrelated charge of setting fire to a car dealership.

The New Haven Register ( ) reports that 51-year-old Nicholas Papantoniou was sentenced to five years in prison after pleading guilty to third-degree arson. Under an agreement with prosecutors, the sentence will run concurrently with the murder sentence.

Authorities say Papantoniou climbed onto the roof of Primetime Auto Sales and Repair in May 2014 and poured gasoline down a vent shortly before the fire erupted. No motive for setting the fire as given.

His lawyer says he denies involvement in the fire but “thought it was in his best interest to accept the plea deal, given the jail credit and his current sentence.”

Information from: New Haven Register,