A man slashed his wife's throat in a fit of jealousy at a popular dessert shop in Phra Khanong district on Saturday morning before trying unsuccessfully to take his own life.
Police rushed to the scene at the Khanom Baan Aiyakarn shop in the PTT service station off the Bang Na expressway in Bang Chak and found the body of a woman lying on the floor in a pool of blood. Lying next to her body was a man with multiple knife wounds. He was rushed to a nearby hospital.
The woman was identified as Walaporn Promtha, 33, an employee of the dessert shop. The man was identified as Somsak Jetkasatkornm 33, her husband and the employee of an S&P bakery outlet.
A sharp knife was found at the scene, along with a two-page handwritten letter in a bag belonging to Mr Somsak. In the letter, he vented his frustration at those who allegedly broke up his family and apologised to his parents for his actions.
Rujira Wongjit, 39, a friend of the woman, told police that a maid at the petrol station saw Ms Walaporn arriving at the shop where she worked at about 7am on Saturday. Mr Somsak, who was already there, dragged her into the outlet, locked the door and closed the curtain.
Because the couple were inside the shop for a long time, the maid became suspicious and looked through a space in the curtain and saw the woman lying in a pool of blood.
The couple had one son, now 4 years old, and quarrelled frequently, said Ms Rujira.
Police said closed-circuit television footage showed the man dragging his wife inside the shop. They quarrelled before the man pulled out a knife to slash her throat before turning the knife on himself.
Officers suspected the motive for the killing was a love triangle. They plan to question more witnesses to find out the cause.