Following the killing of Grosgurin, the Commissioner of the Kammuon District, Phra Yot, was acknowledged by his government to have been the responsible official, although was he initially acquitted of wrongdoing in a trial in March 1894.[8][11] A "Franco-Siamese Mixed Court" was subsequently convened in June 1894.[8] The court determined that Phra Yot had brought extra forces to surround the house in Kien Ket occupied by the ill Grosgurin, outnumbering his small Vietnamese militia; that Grosgurin and those Vietnamese who had not managed to escape had been killed and the house subsequently set on fire on the orders of Phra Yot.[9][12]
In a joint agreement between the Siamese and the French, Phra Yot was condemned to 20 years of penal servitude.[8] The solicitor for the defense was the Ceylonese lawyer William Alfred Tilleke, who was later appointed Attorney General of Siam and granted a peerage by the king.[9][13][14] The Royal Thai Army fort Phra Yot Muang Khwan in Nakhon Phanom Province on the border between Thailand and Laos commemorates Phra Yot.[14]