A policeman shot his wife to death and then turned the gun on himself inside their car in front of their daughter in Narathiwat on Monday evening, police said.
The Sungai Kolok police station was alerted at 5.50pm to the bodies inside a car that had skidded to the side of Prachawiwat road in downtown Sungai Kolok district.
Arriving officers found a 7-year-old girl, Netikan Musukim, crying in the backseat.
The body of Natthanan Trakulprom, 30, was found in the driver's seat. She was shot three times to her head and body.
The body of Pol Corporal Boonyawat Trakulprom, 28, was found in the front passenger seat with a bullet wound to his right temple. A 9mm gun was found on the floor between his legs.
The girl, Natthanan's daughter from a previous marriage, told police that her stepfather had driven to pick up her mother from the school where she taught music and then picked up the daughter from another school.
The stepfather then had his wife take over driving for the trip home, but a quarrel erupted and the policeman shot her, causing the car to skid off the road. The father then shot himself, the girl told police.
Pol Colonel Prayut Pongsanti, commander of the Sungai Kolok police station, said the murder-suicide was motivated by a family quarrel.