A 14-year-old student allegedly killed his grandparents at their home before carrying out a shooting at Debsirin Nonthaburi School in Thailand on Friday, August 7, leaving seven people dead and 23 others injured, police said.

The suspect was among those killed at the school after the attack. Police said he fired at least 26 rounds and was still carrying 34 unused rounds when he was found.

The firearm used in the shooting was legally registered to the suspect’s grandfather.

Lt. Gen. Trairong Phophan, spokesperson for the Royal Thai Police, confirmed that the 14-year-old was among the seven people who died at the school. The victims reportedly included both teachers and students.

Local media images showed the suspect wearing a purple school uniform and a black crossbody bag, with spent bullet casings scattered on the ground.

According to police, the teenager first killed his grandparents at their home in Bang Khu Rat, Bang Bua Thong district, before leaving for school that morning. Their bodies were discovered after police and forensic officers arrived at the residence.

Investigators said the front door of the house had been locked from the outside, leading them to believe the teenager left after his grandparents were killed and then traveled to Debsirin Nonthaburi School, where the subsequent shooting took place.

Police are now examining the teenager’s computer and online activity as they work to determine what may have motivated the attacks.

Initial findings reportedly indicate that he frequently played violent video games and had searched for information about a school shooting in the United States. Those searches were recorded beginning around July 30.

However, investigators have not concluded that video games or the teenager’s search history caused or motivated the shooting. Authorities are continuing to examine other possible factors, including whether he may have experienced problems at school.

The suspect’s uncle told police that the teenager had lived with his grandparents from a young age and generally kept to himself. He reportedly spent much of his time playing video games.

The uncle also said the teenager had no known history of conflicts with others and had not shown any obvious signs of distress before the shooting.

Police said the investigation remains focused on establishing the exact sequence of events and identifying the factors that may have contributed to the attacks.

The school had about 3,100 students and 147 teachers during the 2025 academic year, according to official figures.

The shooting marks Thailand’s second school shooting of the year. In February, a separate incident in southern Thailand left one teacher dead and one student injured.