What happened?
Liam Nebel, an 18-year-old pupil at Brinellskolan, a school in Fagersta, 200km northwest of Stockholm, allegedly entered the school using a key tag, and proceeded to attack people, seemingly at random, with a sword.
Police received the first report of the attack at 2.06pm, and had arrested Nebel by 2.16pm.
Nebel was placed in pre-trial detention on Sunday, according to a press release from Swedish prosecutors.
The local municipality chose to open Brinellskolan and other schools on Monday, although at Brinellskolan the focus is on giving emotional support for pupils.
What do we know about the victims?
One 17-year-old girl died in the attack, with witnesses saying she had been stabbed repeatedly. Two boys, aged 12 and 17 were seriously injured with one requiring emergency surgery. A third teenager, also under 18, was left with more minor physical injuries.
Friends of the dead girl described her as being "sociable and full of energy".
She was studying physics, chemistry and maths, and according to fellow pupils hoped to become a midwife or doctor in Stockholm.
One pupil witnessed the attacker slashing into the back of one of the seriously injured teenagers. The pupil then helped him out to the A-traktor owned by another pupil, who drove the injured boy to hospital, probably saving his life.
What do we know about the motive?
According to witnesses, Nebel wore a helmet, a face mask and black clothing.
This is similar to the uniform worn by Anton Lundin Pettersson, who in 2015 killed three people and injured three more in a similar attack at a school in Trollhättan, before being shot dead by police.
The Dagens Nyheter newspaper reported that an anonymous TikTok account shared a picture of a sword being unwrapped shortly before the attack. According to the newspaper the surrounding room matches the decor in the toilets at Brinellskolan.
According to the Expressen newspaper, Nebel shared videos on TikTok and other social media extolling mass murderers and school attacks, including the shooting in Örebro in 2025, the attack at Malmö Latin in 2022 and Pettersson's attack in 2015. The account also celebrated the terror attack mounted by Anders Behring Breivik in Norway in 2011.
The account also reportedly shared content celebrating the anti-immigration Örebropartiet, the group Alternativ för Sverige, and other far-right content.
Nebel reportedly said in a police interview that he had planned to kill more victims.
What do we know about the perpetrator?
Nebel was a troubled youth who had in 2025 been convicted of assaulting another boy at a school in Fagersta. According to court documents obtained by Expressen, Nebel kicked the boy in the stomach, hit him on the upper body and head, and strangled him with his arm around his neck.
In 2024, Nebel was placed in a foster home was then in 2025 he was moved to another a home under LVU, Sweden's Act on Special Provisions for the Care of Young People.
According to the administrative court's ruling, Nebel had been subjected to physical and psychological abuse at home, had been forced to undergo intensive martial arts training against his will and put on a strict diet to control his weight and appearance.
"The investigation also reveals risk factors in the 18-year-old's own development in the form of his difficulties with impulse control, managing his emotions in a positive way and his mental well-being," the court wrote.
According to the court, he was also prevented from having contact with his mother.
In the fall of 2025, Liam Nebel was convicted of assaulting a boy at a school in Fagersta. He kicked the boy in the stomach and hit him on both the upper body and head, and strangled him with his arm around his neck, according to court documents.
How has Sweden reacted to the attack?
Sweden's education minister, Simona Mohamsson, on Monday said that the government would order a school attack commission "that will propose new measures to prevent future school attacks".
Sweden's Prime Minister Ulf Kristersson and Magdalena Andersson, leader of the opposition Social Democrats, both visited Fagersta together on the day after the attack.
Party leaders cancelled their planned summer speeches this weekend in the aftermath of the attack, with Kristersson, Andersson and Left Party leader Nooshi Dadgostar cancelling speeches planned for Saturday, and Liberal leader Simona Mohamsson cancelling a speech planned for Sunday.
Sweden's King Carl XVI Gustaf expressed his sorrow.
A special church service was held at Brukskyrkan in Fagersta on Sunday, August 23, following the attack, with prayers and the sermon addressing the attack, and a special candle-lighting ceremony.
Hundreds of people have also left flowers, candles and messages in memory of the deceased girl at Brinellskolan.
What happens next?
The school plans to have a memorial day in Fagerstahallen, the municipality's sports and conference centre on Tuesday, August 25th, with students meeting their class-by-class with their teachers and other support staff.
The court has given the prosecutors and police until September 21st to either formally indict Nebel or receive the court's approval to keep him in pre-trial detention.