He was appointed on October 5, 2011 by President Benigno Aquino III as Presiding Justice of the Sandiganbayan replacing Justice Edilberto Sandoval who retired last June 20, 2011.
Justice Villaruz has been an Associate Justice of the Sandiganbayan since 2001.
He took his oath before Supreme Court Chief Justice Renato C.
Corona last October 12, 2011.
His most notable case was the Plunder trial of former President Joseph Estrada, being a member of the Sandiganbayan Special Division that convicted the former President of plunder.