A 64-year-old man shot dead his daughter-in-law and seriously wounded his son and one-year-old grandson before killing himself in a wooded area behind their house in Bangkok's Khlong Sam Wa area on Monday morning, Nimit Mai superintendent Pol Colonel Surapol Komnoi said.
Following the 11.30am report of the murder-suicide at a two-storey house in Bang Chan sub-district, police went to the scene along with rescue workers and a medical examiner.
They found the body of Panadda Aranthong, 26, with three gunshot wounds, including two to her head, while Panadda's husband Pornchai Ariyawong, 31, had been shot once in stomach and their one-year-old son Thannasarn had been shot in the hip. The father and son were taken to hospital.
Officers found the dead body of Jamras Ariyawong, 64, with a single gunshot wound to his head behind the house with a .38 pistol near his body.
A neighbour Wikanda Suwanwong, 28, told police that phone accessory vendor Panadda often complained to her about her frequent arguments with Jamras.
To prevent them from arguing, Panadda and Pornchai did not invited Jamras to join them in an outing, after which he reportedly became angry and attacked them. Wikanda said Panadda had previously told her that her father-in-law often carried a gun while walking around the house and had threatened to shoot them before.
Panadda's father, Prayuth Aranthong, said Jamras had complained to him that Pornchai and Panadda would not let him accompany them on outings. Prayuth also said Panadda had told him she often argued with Jamras and he had threatened to shoot her, but Prayuth thought it was an empty threat and urged her not to worry about it.
Surapol said police initially concluded that Panadda's murder stemmed from a domestic conflict and Jamras's death was a suicide, but they planned to interview Pornchai when he recovered from his injuries.