A 21-year-old former Nagoya University student has appealed a district court ruling that sentenced her to life in prison over the 2014 murder of an elderly woman and the attempted murders of two teens when she was in high school, court officials said Thursday.

The appeal was filed with the Nagoya High Court on Wednesday. The defense counsel for the woman, whose name is being withheld because she was a minor when the crimes were committed, declined to comment on the reason for the appeal.

While the defense had sought acquittal in regional court hearings — claiming the woman had been suffering from a severe mental disorder — the Nagoya District Court said in its March 24 ruling that she was mentally competent and that her disorder did not significantly influence her actions.

According to the district court ruling, the former student murdered Tomoko Mori, 77, in Nagoya in December 2014, and tried to kill a female junior high school classmate and a male high school classmate sometime between May and July 2012 in Sendai, Miyagi Prefecture, by poisoning them with thallium.