By The Nation
The body of Pichai Phethet, 53, was found at 6am on a ground in front of a three-story building at Chumpae Witthayayon School in Ban Phaikudhin, Chumpae district.
A doctor who examined the body at the scene estimated the teacher had been dead for about three hours.
A Wi-Fi router was found nearby.
Security guard Boonsong Thanomphol, 57, who discovered the body, told police Pichai had stayed overnight at the school because he wanted to set up routers before the new semester began on May 15.