Hideaki Kumazawa, a former top bureaucrat at the farm ministry, was indicted Friday for the murder of his 44-year-old son at their home in Tokyo.
According to the indictment, the 76-year-old stabbed Eiichiro Kumazawa in the neck multiple times around 3:15 p.m. on June 1 and then called the police to say he had fatally stabbed his son, who later died in hospital due to massive blood loss.
Hideaki Kumazawa later explained that his action was prompted by fear his son might harm children, seeing similarities with the case of Ryuichi Iwasaki, who stabbed a group of school children with a knife earlier that week, according to investigative sources.
He heard his son say he would "kill" students when he became incensed by the noise from an athletic meet at an elementary school near their home, according to the sources.
The man said his son was socially withdrawn and had exhibited violent behavior toward him and his wife.
Iwasaki, who stabbed Caritas Elementary School students and a parent in Kawasaki near Tokyo on May 28, hardly left his home in which he lived with his aunt and uncle, according to officials of the city's mental health and welfare center.
A graduate of the University of Tokyo, Hideaki Kumazawa joined the predecessor of the farm ministry in 1967 and became its vice minister in 2001.
He stepped down the following year amid criticism over the ministry's handling of mad cow disease.
He served as Japan's ambassador to the Czech Republic from 2005 to 2008.