The parents of a teenage gunman who killed eight people in a shooting at a school in Thailand have apologised 'to society'. The father of the 14-year-old, who also shot and killed his grandparents before going on the killing spree at his school on Friday, expressed remorse for what his son had done, Thai media reports.The shooting at Debsirin Nonthaburi School on the outskirts of Bangkok initially killed five members of staff and two children, before a 12-year-old girl was also confirmed to have died on Saturday.Some 22 others were wounded, with 14 still in hospital and seven of those in a critical condition.The shooter turned the gun, which was registered to his grandfather, on himself before he could be arrested. Thai police called the teenager's parents, who were described as extremely stressed and not willing to speak to reporters, in for questioning today.The boy's father told officers during his interview session that he apologised to society for what his son had done, local media reported, adding the man saw his son's body only when preparing for his funeral later on Saturday.Friday's attack marked the worst mass shooting since 2022, and has reignited debate about gun laws in the country. The father (pictured) of a teenage gunman who killed eight people in a shooting at Debsirin Nonthaburi School on the outskirts of Bangkok has apologised 'to society' for his son's actionsNewly emerged images show the suspect, dressed in the school's purple uniform, stalking the corridors of Debsirin Nonthaburi School on the outskirts of Bangkok The images capturing the shooter were taken before he turned the gun on himself The suspect was reportedly seen reloading ammunition inside the building, and is now known to have killed eight people at the school as well as his grandparents. Pictured: The gun used in the shooting The shooter's parents were both questioned by Thai police, it has been confirmedOn Saturday it was confirmed that a third pupil, a girl aged 12, has died from critical wounds.The 14-year-old, who has not been named, killed his grandparents at their family home before travelling to school and opening fire at around 10am on Friday. He then took his own life.After the shooting the school made a social media appeal for blood donations for two injured students, including the seventh grade girl who has now died.Fourteen people remain hospitalised, of whom seven are in a critical condition, according to Thailand's Health Ministry. Most of those wounded were between 12 and 14 years old.Relatives have already claimed the bodies of some of the shooting victims, as well as the teenager who committed the atrocity and his grandparents. The young girl's body is still to be released.Wiroon Supasingsiripreecha, head of Bangkok's Institute of Forensic Medicine, said most of the victims suffered a single fatal gunshot wound to a vital area, including the chest or head.He said the gunshot wound found on the alleged shooter was consistent with the weapon he had used. More detailed forensic findings, including toxicology results, are expected later, he said.Officials said the gun, described as small and compact, was legally registered to the boy's grandfather.There were reports that the boy had shown signs of stress connected to school, although some of his relatives told Thai media that they were unaware of any troubles he might have been facing. A pupil reunites with a relative after being evacuated from Debsirin Nonthaburi School