The gunman behind a massacre in Thailand that killed at least 36 people had a history of drug offences and violence, police said on Thursday.
Panya Khamrab, 34, stormed a nursery in Nong Bua Lamphu, northern Thailand, and killed 24 children, as young as two years old, among 38 killed overall with 18 injured.
The perpetrator then drove home to turn the gun on himself, his wife and his child.
Details have emerged about the murderer's past, including an arrest and charge for drug abuse and possession in 2021, which led to his dismissal from government service.
Mr Khamrab joined government services a decade ago in 2012, first as the commander of the Yannawa Police Station in Bangkok before moving to Na Wang Police Station, in the same town as the rampage, in 2019.
Local Thai news site Khaosod Online reports that the former police officer had problems with his girlfriend because he refused to move in together.
This was when he began to engage in drug-related behaviour and it was not until he suddenly lost loads of weight that his fellow police officers began suspecting he was a drug abuser.
However, they were too afraid to get involved.
Mr Khamrab started acting out of line and refused to obey the orders of his superiors. It has been reported that on one occasion, the supervisor told him to go and respond to an incident at the Government Savings Bank, but instead of going on-site he fell asleep in the car parked in front of the bank.
Eventually, he went to help the manager of the bank escort a large sum of the movement of money into the ATM but suddenly pulled a gun on the manager.
Mr Khamrab started dating another unnamed woman who worked at the local karaoke bar.
Khaosod Online reports that she is the former girlfriend of a drug convict who is currently imprisoned at Nong Bua Lamphu Provincial Prison.
The couple would regularly hold parties together, causing a ruckus and making loud noise which was troublesome to police officials and nearby villagers, it has been reported.
Mr Khamrab supposedly would pull out a firearm so that no one would interfere with the partying.
One night it got out of hand and a policeman gave Mr Khamrab a warning which he did not respond well to.
Police Colonel Suwatchai Malithong summoned Mr Khamrab to the office for an enquiry and the gunman then admitted to having used drugs since high school and promised his superiors that he would stop taking drugs.
When arrested and questioned, Khaosod Online reports that he said: "I've been smoking methamphetamine for a long time. In the past, there were hundreds of methamphetamines. I didn't see anyone arrested.”
He was later dismissed from the force due to drug use, said police colonel Jakkapat Vijitraithaya.
Mr Khamrab was facing trial on drugs charges and had been in court in the hours before the shooting, a police spokesperson told broadcaster Thai PBS.
He had come to collect his child from the daycare centre but opened fire when he did not find the child there, the spokesperson said.
District official Jidapa Boonsom, who was working in a nearby office at the time, told Reuters: "The shooter came in around lunchtime and shot four or five officials at the childcare centre first.
"At first people thought the shots were fireworks. It's really shocking. We were very scared and ran to hide once we knew it was shooting. So many children got killed, I've never seen anything like it."
The attacker forced his way into a locked room where children were sleeping. Ms Boonsom said she thought he killed children there with a knife, adding that a teacher who was eight months pregnant was also killed with a knife.
Drugs Charge Prime Minister Prayuth Chan-Ocha said in a statement on Facebook that the shooting was a "shocking incident".
He continued: "I have ordered the police chief to travel to the scene immediately to take necessary actions and all involved parties to provide immediate relief to all affected people."
