Lawyer Craig Penglase plans to explore mental-health issues as he defends 24-year-old James Troutman in the May 9 slaying.
Troutman is charged with killing Skyler Kauffman at their Souderton apartment complex.
Penglase says his client will waive his right to a preliminary hearing Monday.
He says Troutman may have the social disorder Asperger's syndrome, but will also be tested for mental illness. He says Asperger's alone wouldn't prevent him from knowing right from wrong, the standard for an insanity defense in Pennsylvania.
Penglase previously won an insanity defense for a woman accused of trying to kill her newborn. She got probation.