Maine’s highest court is hearing an appeal from a Maine man who’s serving a 35-year sentence for fatally shooting a rival on a Bangor street. Justices on Thursday will hear the appeal of 21-year-old Zachary Carr, who was convicted last year in the January 2010 death of 19-year-old John “Bobby” Surles. During Carr’s trial, a prosecutor said Carr “executed” Surles while he was lying helplessly on the ground, but Carr testified his gun accidentally discharged while defending himself. In his appeal, Carr contends the lower court erred by not granting him a new trial based on the state’s failure to disclose a recorded interview with a key witness. He’s also challenging whether there was sufficient evidence to convict him and how various factors were determined in calculating his sentence.