An elderly man was stabbed to death with a knife by his 15-year-old grandson in Phitsanulok on Tuesday night, police said.
Police found Hiang Pimpan, 80, lying dead inside his house with knife wounds to his head and body.
Hiang's wife, Sawang, said their 15-year-old grandson Thanwa Dathong lived with them. He was mentally ill and frequently flew into rages and quarrelled with his grandfather.
On Tuesday night, Thanwa again quarrelled with her husband. The boy became very angry and rushed to get a knife. He then attacked and repeatedly stabbed his grandfather, who fell to the floor and died, Mrs Sawang said.
Police detained the teenager for questioning.
