The Royal Thai Police will discuss the matter with the Ministry of Interior and other organisations involved in the registration of firearms, he said, reports the Bangkok Post.
Deputy Prime Minister and Public Health Minister Anutin Charnvirakul said six forensic medical examiners from provinces near where the shooting occurred have been called in to help identify the bodies of those who died as their relatives are eager to reclaim them for funeral rites.
After the examinations are done, the corpses will be taken back to Nong Bua Lam Phu from Udon Thani, he added.
An examination of the body of former Pol Sgt Panya Khamrab, the gunman, may take longer than usual as a thorough probe is required to find out more information about the trajectory of the bullet that entered his body, said the minister.
His motive for attacking the preschool, which resulted in 37 casualties, including the perpetrator’s wife and child, is unclear but authorities suspect he chose what he considered to be an easy target, said deputy national police chief Pol Gen Torsak Sukwimol.
According to police, 23 of those killed at the centre were children. At least another 10 were injured, six seriously.
A preliminary investigation showed the gunman was in and out of the nursery within four minutes, suggesting he had already mapped out the location and selected it earlier, said Pol Gen Torsak.
Police were alerted by the time he left the premises but the nearest station is located 15 kilometres away, he said, adding officers still managed to arrive at the crime scene within roughly 10 minutes of being dispatched.
Pol Gen Torsak also cited a study by the FBI while attempting to analyse why the killer carried out the attack.
Three main factors were identified in the US study.
The “inside factor” could be a psychological problem, vulnerability and substance-induced psychosis, while the “outside” factor may include family, social and economic pressure, Pol Gen Torsak said, referring to the first two factors.
The third factor refers to a situation that could provoke the attacker’s impromptu violent response to it, he added.
The mother of the gunman confirmed her son was a methamphetamine addict and that he was due to appear in court yesterday in a drug case that would likely have added to the stress he was feeling.
Apologising to all those affected by her son’s attacks, the woman said her son had been under a great deal of stress since he lost his job and was incapable of repaying his debts.
He was booted out of the police force on June 15 after he was caught in possession of methamphetamine pills in January.