This morning a panel of NC Supreme Court justices will hear oral arguments in the case of Joshua Andrew Stepp, the Raleigh Iraq War veteran convicted for sexually assaulting and beating to death his 10-month-old stepdaughter in 2009.

In 2011 Stepp was found guilty of felony murder and sentenced to life in prison after a jury ruled that he killed the infant while committing a sexual offense. Last January, the NC Court of Appeals reversed the conviction and ordered a new trial. The appellate court ruled, in a 2-1 split, that the trial judge failed to instruct the jury on an affirmative defense to the underlying felony of sexual offense.

Evidence showed that the baby sustained injuries to her head, back, rectal and genital areas. Stepp admits to killing the girl, but said he did it accidentally, in attempt to stop her from crying and choking, after several failed attempts at changing her diaper. He denied sexually abusing the girl, arguing that the genital injuries were due to his attempt to clean the child’s feces and urine, in order to prevent infection. Stepp’s attorneys say his military-related PTSD also played a role in the killing.

In reversing the trial court’s decision, the Court of Appeals ruled that Judge W. Osmond Smith III should have told the jury that the defense to this particular felony murder scenario was that Stepp penetrated the infant’s vagina for “accepted medical purposes.” (Stepp had requested this jury instruction, but Smith denied it.)

Following the Court of Appeals reversal, Roy Cooper’s office appealed the case to the NC Supreme Court. State’s lawyers argue that that the act of cleaning feces, standing alone, should not be considered an act performed for an acceptable medical purpose.