Twenty-five-year-old Shannon Johnson was sentenced to death last year for the 2006 murder of Cameron Hamelin. Hamelin was shot while sitting in his car in Wilmington with Johnson's ex-girlfriend, Lakeisha Truitt.
Johnson shot Truitt a few weeks after Hamelin's murder, but she survived and testified against him.
In sentencing Johnson to death, the judge noted his long criminal history, including the 2002 rape of a teenager who was seven months pregnant.
Johnson argued on appeal that the trial court should have excluded certain evidence, including details about the rape conviction.