The Austrian shooter responsible for killing 10 people at his old school, before taking his own life, had apparently shared photos on social media of his preparations and the weapons he used, it has been revealed.

Arthur A., a 21-year-old who enjoyed gaming and adored cats, executed the attack at the BORG Dreierschutzengasse high school in Graz, located in the southern state of Styria, on Tuesday.

The shooter shared an image of his own feet clad in black leather combat boots while sitting in a toilet cubicle on the third floor of the school.

Equipped with a gun belt, hunting knife, shooting glasses, and a headset, he loaded his firearms and entered the hallways, executing the massacre, which was later recognized as Austria’s deadliest mass shooting. 

In two other posts, the young killer snapped a selfie and showed off a shotgun and a pistol he had bought along with the caption: ‘Veeeeeerrry early birthday present for myself’, according to Austrian media. 

He went on to use both weapons in the course of his rampage.

The images of the killer were brought to light after it emerged the social recluse had sent his mother a farewell video moments before he carried out his attack, pleading for forgiveness for ‘what I’m about to do now’.

Investigators said his mother opened the video 24 minutes after receiving it and immediately notified police, but her son had already slaughtered 10 students and shot himself before armed cops descended on the scene.

Arthur A. also requested that his cat be looked after following his demise and said that bullying at school had caused him to drop out early and led him to commit the heinous crime.

‘A farewell letter in analogue and digital form was found,’ Franz Ruf, the public security director at Austria’s interior ministry, told ORF public television following the shooting.

‘He says goodbye to his parents. But no motive can be inferred from the farewell letter, and that is a matter for further investigations.’

Asked whether the assailant had attacked victims randomly or targeted them specifically, Ruf said that is also under investigation and he didn’t want to speculate.

He said that wounded people were found on various levels of the school and, in one case, in front of the building.

The student victims were aged between 14 and 17. A teacher was also killed.

In new details, investigators said the gunman, who would have turned 22 in less than two weeks, had maintained contact with only one friend in the days leading up to the attack.

Mayor of Karlsdorf, a small town near Graz where the killer lived, told reporters the evidence suggested that Arthur A. ‘was a very inconspicuous young man’.

‘It felt like he wasn’t even noticed. Nobody really knew him. This is exactly the profile that we unfortunately see too often – silent, socially isolated recluses.’

Austrian outlet Kronen Zeitung said the killer had an interest in the 1999 US Columbine school massacre in Colorado carried out by two teenage shooters and that he apparently used a photo of one of the pair on a profile linked to his online gaming pseudonym.

Police are continuing to scour the shooter’s electronic devices but said yesterday they had not discovered any video of the high school shooting on his mobile phone.

Criminal police head Michael Lohnegger described the shooter as a ‘very introverted person’.

‘We discovered that his great passion was participating in so-called online first-person shooting games,’ Lohnegger said, adding the killer had carefully planned the attack, according to a handwritten note found at his home.

This note ‘showed that the entire course of events had been planned by the perpetrator down to the most minute detail’, Lohnegger said.

Austrian media published photos that showed the killer being lauded for his exploits as a competitive gamer.

Arthur A. was seen wearing a yellow and black team jersey at an Austrian gaming tournament called VulkanLAN2024 last year. He was also pictured clutching what appeared to be a winning plaque.

Nine students were killed in Tuesday’s attack – six girls and three boys aged between 14 and 17, one of whom had Polish citizenship – as well as a teacher, police said. 

Another 11 people were wounded before the attacker took his own life. 

A 15-year-old Kosovan girl named Lea Ilir Bajrami was the first of his victims to be pictured. 

Mourning the teen in a Facebook post, her heartbroken aunt wrote: ‘Today, my niece Lea tragically lost her life in the attack in Graz. 

‘We pray for her soul and express our gratitude to all those who share our pain during these difficult times.’

Her grandfather Muhabi Bajrami wrote on Facebook: ‘With a broken heart and great pain, we inform family, friends and relatives that our granddaughter tragically lost her life in the attack that occurred in Graz, Austria.

‘We pray for her soul and express our gratitude to all those who share our pain in these difficult moments.’

Shots and screams rang out as the shooter stormed into his old classroom blasting a shotgun and a pistol.

Terror-stricken pupils pretended to be dead as they cowered in corridors and two classrooms or ran for their lives.

Chilling video captured the sound of shots followed by screams as the gunman picked off his victims.

One student fleeing from the shooter called her mother during the attack saying: ‘Mama, mama, I’m running for my life!’

The mother described the situation to reporters as unbearable, saying: ‘It was so terrible, you can’t even imagine it.’

Another student reportedly witnessed three classmates being shot. His father said: ‘He was terrified and lay down on the floor so the shooter would think he was dead.’

The school’s religious studies teacher Paul Nitsche told how he saw the gunman blasting out locks with a shotgun before entering and spraying staff and students with handgun bullets.

‘It was hard to take in,’ he said. 

‘This is something I had never even imagined before. That’s what the situation was like as I was running down the stairwell – I thought to myself, this isn’t real.’

Another teacher, who asked not to be named, said: ‘The whole community is in a state of shock. Schools should be places of safety and learning. But on this day it became more like something from a nightmare. 

‘Everyone was in a state of sheer terror.’

On Tuesday, Cchurch bells rang across the city of Graz, all local radio and TV broadcasts were interrupted and more than 900 public transport vehicles, including trams and buses, ground to a halt for 10am mark of remembrance. 

Two other schools in the city, including a nursery school, were evacuated today after they received ‘copycat’ threats shortly before the planned minute’s silence, though no further attacks occurred. 

Six female and three male victims died quickly after being shot, with one adult said to be among them. 

The victim, a student, succumbed to her injuries in hospital later on Tuesday.