Police set up checkpoints at all piers on Koh Samui to look for the gunmen, who police believe are professional assassins.
Provincial chief Pol Maj-General Apichart Boonsriroj said police found from security camera footage that a man in his 40s had allegedly scouted the area an hour prior to the shooting. The footage also showed that two gunmen opened fire from in front of the restaurant at the victims who were having drinks inside before shooting Panas at close range and fleeing from the scene. Autopsy showed that Panas had sustained six gunshots from the back.