A former student who killed nine students and a teacher in Austria a week ago and then took his own life had become fascinated with school shootings in recent years, but his motive for the rampage remains unclear, investigators said Tuesday.
Police have said the 21-year-old gunman planned last Tuesday's roughly seven-minute attack at the BORG Dreierschützengasse high school in Graz, which he left three years ago, down to the smallest detail. But much remains uncertain: among other things, why he chose that particular date and why he stopped shooting when he did.
