A Manchester, Iowa, teenager agreed to plead guilty Monday to two charges of first-degree murder, according to the Associated Press.

Isaiah Sweet’s trial ended before the defense called any witnesses.

Sweet, 18, was charged in May 2012 with killing his grandparents, 55-year-old Richard Sweet and 62-year-old Janet Sweet.

Manchester police responded to a call from 109 Deann Drive in Manchester on the afternoon of May 13, 2012, where officers found Janet and Richard Sweet dead.

Isaiah Sweet at the time was missing; he was located two days after the slayings in the Cedar Rapids area by a Cedar Rapids police officer.

According to the Associated Press, Isaiah Sweet’s sentences will run concurrently.

— by Kristen East