John Lee Cowell doesn’t deny killing Nia Wilson, 18, and injuring her sister Letifah, but neither does he take responsibility for his actions, claiming he is not guilty by reason of insanity. His defense attorney previously entered the plea on his behalf, but Cowell, 29, showed up to a hearing

It was nearly a year ago when Nia Wilson, 18, was murdered and her sister Lahtifa Wilson, 26, was injured in a “prison-style attack” on the MacArthur BART platform. An Alameda County Superior Court judge ruled Wednesday that the suspect in Wilson’s murder is mentally competent enough to stand trial.