An auto tire repairman pummelled his young wife to death with a steel bar before shooting himself in the head with a shotgun in Khao Yoi district on Saturday night, police said.
The incident was reported to the 191 emergency centre at about 8.39pm.
This prompted Khao Yoi police, led by Pol Lt Col Sompong Khamthawee, and rescuers from a local charity foundation, to rush to an auto tire repair shop on Phetkasem road in tambon Thap Khang, Khao Yoi district, where the incident occurred.
Wichai Leeka, 43, and his wife Thanthip Pothong, 21, were found lying dead in the shop.
Wichai shot himself in the head with a shotgun.
The body of Thanthip was found lying nearby, with her behind her back. Her head and body had been hit many times with a hard object.
The shotgun and a steel bar with blood stains on it were found in the shop.
Police were first alerted by a male relative of Wichai, who told police that he received a telephone call from another relative who lived in Ayutthaya.
That person said Wichai had just called him and said he had killed his wife and was about to take his own life.
The man rushed to the shop and knocked on the door, but received no answer. He then called police.
When officers arrived, they broke open the door and found found the bodies of Wichai and his wife.
An investigation was underway to establish what led to the murder-suicide.