By Elizabeth Daley
PITTSBURGH (Reuters) - A Pennsylvania man has been found guilty but mentally ill in the sword-stabbing murders of his parents and twin brother, his lawyer's office said on Thursday.
Joseph McAndrew Jr., 27, was convicted on Wednesday by Judge Gary Silow in Montgomery County Court of the March 2011 slayings after a seven-day trial. He had waived a jury trial.
He faces life in prison or in a mental facility, authorities said.
McAndrew was found guilty of killing his twin brother, James McAndrew, and his parents, Susan and Joseph McAndrew Sr., in the Philadelphia suburb of Gulph Mills, according to the office of his defense attorney, Paul Bauer.
A tenant of the family called 911, Assistant District Attorney Kevin Steele said, and McAndrew was arrested outside their home while trying to flee and told police that his family members were away when they lay dead inside.
A bloody sword, which McAndrew had used to stab his family, was found inside the house, according to prosecutors.
The issue raised throughout the trial was not McAndrew's guilt but his mental competency, Bauer's office said. McAndrew had gotten various mental health diagnoses and was collecting disability payments for his illness, it said.
McAndrew has been held in a locked ward at Norristown State Hospital, Steele said.
A court-ordered psychiatric evaluation will take place before his sentencing, the prosecutor said. No date for the sentencing was set.
(Editing by Ellen Wulfhorst and Mohammad Zargham)