With their son in federal custody and a memorial service for the six victims he's accused of shooting scheduled for Wednesday, the parents of Jared Loughner have broken their silence.

"There are no words that can possibly express how we feel," they wrote in a statement handed to reporters stationed outside their home. "We wish that there were, so we could make you feel better. We don't understand why this happened.

"We care very deeply about the victims and their families. We are so very sorry for their loss."