An Indiana teenager has admitted shooting a classmate and faces decades in prison. Michael Phelps admitted in a Martinsville courtroom Monday he shot Chance Jackson at their middle school March 25 and intended to kill him, The Indianapolis Star reported. Both boys were 15 at the time. Jackson survived but is still recovering. Morgan County Superior Court Judge G. Thomas Gray declared Phelps guilty of attempted murder and will sentence him next month. Phelps' maximum sentence is 20 to 50 years in adult prison, but prosecutor Steve Sonnega says he will not request it. In view of Phelps' age, lack of a prior record and confession, he is likely to get 30 years or less, said Joel Schumm, a professor at Indiana University School of Law-Indianapolis. Phelps' attorney, Steve Litz, is hoping for 20 years, with release possible after eight for good behavior and schooling. He will call the boy's family and a psychiatrist testify about his troubled background.