The motive remains unclear for a shooting range attack by a Ground Self-Defense Force cadet in Gifu a week ago that killed two GSDF members and injured another.
The 18-year-old suspect has not expressed to investigators any dissatisfaction with the three or the GSDF.
The GSDF's military police and the Gifu Prefectural Police are considering having the suspect undergo psychiatric evaluation to determine whether he is mentally competent to be held criminally responsible.