Trial May 6in mailbox bombFLORENCE (AP) - Wil-liam L. Webb, 20, was ordered Tuesday to face trial May 6; in Pinal County Superior Court for the attempted murder of his father,*; Webb is accused of placing a package bomb in a mailbox at the home of Newell Webb, 41, of Casa Grande. The elder Webb opened the package in his living room Jan. 22 and it exploded, investigators said.Webb’s arms were amputated at the elbow. He received extensive treatment at a Phoenix hospital.Judge T, J. Mahoney ruled earlier this month that the . younger Webb is mentally able to stand trial.