HILLSBOROUGH, N.C. — Attorneys for a Chapel Hill teenager claim their client allegedly killed his parents in self-defense, according to court notices released this week.

Attorneys wrote in the documents five different trial defenses for Adam Sapikowski, including four regarding his mental health. Those defenses include insanity and diminished capacity.

Sapikowski is accused of shooting his parents, James Sapikowski, 52, and Allison Sapikowski, 49. In May 2005, both were found wrapped in blankets behind a barricaded door in their Chapel Hill home. Police believe their bodies had been there for weeks.

The mental-health defenses could be used together, but the self-defense argument would have to be used separately. Depending on what the presiding judge in the case decides, the attorneys might not have to choose which defense they use until right before the jury deliberates.

The insanity and the diminished capacity defenses could be critical in trial. They allow a jury to find someone not guilty by reason of insanity. With a diminished capacity defense, a jury could elect to convict someone of a lesser charge.

Sapikowski's attorney, Johnny Gaskins, told WRAL that his client's father threatened his son with a bat. An aluminum baseball bat was one of several items investigators took from the crime scene.

In a previous court proceeding, Sapikowski's original court-appointed attorney, James Williams, told a judge that the shootings were provoked and that "some elements of physical and emotional abuse led up to the killings."

Now 17, Sapikowski has undergone psychological evaluations, and at one point, was under a suicide watch at Raleigh's Central Prison.

In mid-September, Sapikowski was moved from the Orange County Jail to Umstead Hospital in Butner after he told jail officials that he was afraid he would end up doing something "crazy" to himself.

A hospital psychiatrist said Sapikowski suffered from post-traumatic stress disorder and has had flashbacks of killing his parents.