MANCHESTER, Iowa (AP) -

A Manchester man sentenced to life without parole for killing his grandparents has filed an appeal.

The Dubuque Telegraph Herald reports that attorneys for 19-year-old Isaiah Sweet filed notice of appeal on Thursday, 10 days after Sweet was sentenced to life for the May 2012 shooting deaths of Janet and Richard Sweet at their Manchester home.

Sweet had pleaded guilty to two counts of first-degree murder.

His lawyers are likely to argue in the appeal that a sentence of life without the possibility of parole is excessive, because Sweet was 17 when he killed his grandparents.

Recent rulings from the U.S. Supreme Court and the Iowa Supreme Court require judges to consider whether teenage offenders can be rehabilitated. The judge is Sweet's cased deemed he could not be.