The 14-year-old boy accused of carrying out a deadly school shooting outside Bangkok had previously brought an air gun to school, which was confiscated by a teacher last year, according to Thai police.
Authorities also said the teenager had watched violent content online and allegedly used social media to learn about firearms before Friday’s shooting spree.
Police said the teenager allegedly killed his grandparents at their home before going to his school, where six more people were killed. He later died after turning the firearm on himself. More than 20 others were injured in the incident.
Provincial Police Region 1 deputy commissioner Atthapol Anusit said investigators had interviewed 17 witnesses and found evidence suggesting the teenager had been interested in learning about firearms for around one to two years.
An examination of his personal computer reportedly showed that he had watched violent material on social media. However, police said they had yet to find evidence confirming that he had practised shooting.
A knife was also reportedly found in his school bag, while investigators recovered a firearm, spent cartridge cases and other evidence from the crime scenes.
The teenager had lived with his grandparents for around 12 years after his parents separated, police said.
His mother, however, told Reuters that she had not noticed any troubling behaviour. She described her son as bright and cheerful and said he had always told her that he was not being bullied.
She said she only realised he might have been involved after hearing about the shooting and attempting to contact him. She sent him messages and called him, telling him to contact her if anything was wrong.
The Ministry of Education has announced plans to introduce new school safety measures over the next three months. These include mental health screenings, referral systems for students considered at risk, emergency response drills, stronger anti-bullying measures and improved checks to prevent weapons or other dangerous items from being brought onto school grounds.
The shooting has renewed concerns over gun control in Thailand, which has one of the highest rates of civilian gun ownership in Southeast Asia.
The teenager’s mother said the family was devastated by the tragedy and apologised for her son’s actions.
