A 14-year-old boy accused of carrying out a deadly shooting at a school in Thailand had reportedly learnt how to handle and use firearms through social media, police said as investigators continued to examine the circumstances surrounding the attack.

The teenager allegedly killed his grandparents at their home before going to Debsirin Nonthaburi School in Nonthaburi province, near Bangkok, where he opened fire.

Eight people, including the teenager, were killed in the incident, while more than 20 others were injured.

Investigators are now examining the teenager's digital activity, family circumstances and relationships with classmates as they try to determine what led to the shooting.

Police Examine Online Activity

Senior police official Atthapol Anusit said investigators had questioned 17 witnesses as part of the probe.

Police believe the attack may have been planned, although authorities have not yet established a definitive motive.

Investigators examining the teenager's computer reportedly found violent material that he had accessed through social media. Police also believe he used online content to learn about firearms.

Authorities, however, have not found evidence that the teenager underwent formal firearms training or regularly practised shooting at a range.

The investigation is continuing to determine how he acquired the knowledge and access needed to use the weapon.

BB Gun Had Been Confiscated

Police said the teenager had previously brought a BB gun to school, prompting a teacher to confiscate it last year.

The air gun had reportedly been purchased online.

Investigators have since collected the firearm allegedly used in the latest attack, along with spent cartridge cases and other items recovered from the scene.

The teenager's mobile phone and computer are also being examined as police attempt to establish his activities and communications before the shooting.

A knife found inside the bag he carried to school has also been taken as evidence.

Family Background Under Investigation

The teenager had been living with his grandparents since he was about two years old after his parents separated.

According to police, he allegedly used a handgun belonging to his grandfather to shoot his grandparents at their home before travelling to the school.

He then allegedly opened fire on teachers and students before turning the weapon on himself.

Police are examining whether academic pressure, family circumstances, disagreements with friends or exposure to violent material online may have played a role.

Authorities have not confirmed that any one of these factors was responsible for the attack.

Mother Expresses Shock

The teenager's mother told Reuters that she was devastated by what had happened.

She described her son as a bright and cheerful child who appeared to behave normally and said the family had not anticipated such an incident.

The boy's father has also reportedly apologised for his son's actions, according to local media.

A teacher who knew the teenager described him as a good student who performed well academically. Education officials also said he was an avid gamer.

Prime Minister Anutin Charnvirakul has suggested that the teenager's grandmother, who worked as a teacher, may have been strict with him, although authorities have not established whether this had any connection to the shooting.

Focus Turns to Gun Safety

The attack has renewed concerns about firearm access and school security in Thailand.

Thailand has one of the higher levels of civilian gun ownership in Southeast Asia, and previous shootings have repeatedly prompted debate over tighter controls and safer storage of firearms.

The latest case has also brought renewed attention to the influence of violent online content and the ability of young people to access information about weapons through digital platforms.

The government has said it plans to introduce additional measures aimed at improving firearm safety and strengthening security around schools.

For investigators, the immediate priority remains establishing how the teenager obtained the weapon, what he did online before the attack and whether anyone else was aware of his plans.

The findings could influence the government's response to both firearm access and online exposure among young people following one of Thailand's latest school shooting tragedies.