Pol Colonel Kritsana Pattanacharoen, deputy police spokesman, said the five people – a grandfather, grandmother, mother, father and a nine-year-old boy – were killed in their home in Suksawat alley at around 8.30am on Thursday (September 17).
The family had been running a chemical business from the house.
The forensic team collecting evidence from the crime scene found a gun in the hand of the boy’s father, who was identified as “Lek”.
Neighbours said they heard the grandmother shout: “Lek, you’re hurting me.”
Police believe Lek may have been facing financial stress and decided to murder his father, mother, wife and son before killing himself.