A Quincy, Mass., woman was found not guilty by reason of insanity in the death of her 8-year-old son in 2011, the Norfolk County prosecutor\'s office said. After the one-day, bench trial in Norfolk Superior Court, Judge Robert C. Cosgrove ruled Tuesday Li Rong Zhang, 42, was not criminally responsible for the death of Brandon Yang, The Boston Globe reported Wednesday. The trial included testimony the defendant suffered from psychotic depression, paranoid delusions, paranoid schizophrenia and acute suicidality, District Attorney Michael W. Morrissey\'s office said. \"Her mental illness had a significant impact on her ability to understand the wrongfulness of what she was doing,\" Zhang attorney James Doyle said. Prosecutors alleged Zhang barricaded herself and her son in her bedroom Jan. 13, 2011, and tried to kill them both by filling the room with carbon monoxide by burning charcoal in a wok. David Traub, a spokesman for the prosecutor\'s office, said doctors for both the defense and the prosecution reached consensus that Zhang should not be held criminally responsible. \"All of the evidence presented both by the prosecution and defense to Judge Cosgrove was uniform,\" Traub said. Doyle said the decision \"was a just verdict and it recognized that it was tragedy, not a crime.\" After the verdict, Zhang was transported to Worcester State Hospital, prosecutors said. She will be hospitalized for as long as 40 days pending an evaluation, after which she will be held indefinitely or released, depending on whether she is considered a threat to herself or others, the Globe said. If she is held, she will have the right to periodic reviews.