A former top bureaucrat at the farm ministry admitted Wednesday to killing his socially reclusive son, during the first day of his high-profile trial in Tokyo.

Hideaki Kumazawa, 76, who once served as vice minister at the Ministry of Agriculture, Forestry and Fisheries, is on trial for stabbing his 44-year-old son, Eiichiro, in the neck multiple times at around 3:15 p.m. on June 1, causing his death from massive blood loss, according to the indictment.

Prosecutors said the defendant feared for his own safety before deciding to kill his son, who had displayed violent behavior in the family home ever since he was bullied at a famous private junior high school.