Finland had not experienced terrorist attacks and had faced very little political violence since the end of World War II.

In June 2017, the Finnish Security Intelligence Service assessed the overall terrorist threat as level two ("elevated") on its four-tier scale.

"[10][11][12] He had previously lived as an illegal alien in Germany and had committed crimes there under several different identities from the end of 2015 until early 2016 without seeking asylum.

[16][13] According to persons interviewed at the Pansio asylum-seeker reception centre by national broadcaster Yle, Abderrahman Bouanane arrived at the centre in December 2016 and displayed radicalist behaviour during his stay, such as asking how he could join the Islamic State of Iraq and Syria (ISIS), listening to radicalist sermons on his phone and considering Finns to be infidels (kuffār).

[20] According to concluding remarks by the Finnish National Bureau of Investigation (NBI) after the case was closed, Bouanane told during his interrogations that he started having an interest in ISIS propaganda three months prior to the attack.

Bouanane possessed ISIS material, such as photos and videos, on his mobile phone and his computer; his close friends believed he displayed signs of radicalization.

Bouanane saw himself as a soldier of ISIS and said one motive for his attack were airstrikes by the Western Coalition during the 2017 Battle of Raqqa in Syria.

[21][4][22][23] Around noon of 18 August 2017, Abderrahman Bouanane took two kitchen knives with him and cycled from a friend's place in Kaarina to downtown Turku, where he attended a Muslim prayer at a mosque next to the river Aura.

The manifesto was religiously inspired and contained, among others, discussion on the infidelity of Western nations as well as how oppressed Muslims should act.

Next, he moved to the local bus station where he intended to attack a military conscript, believing a soldier to be a valid target.

[28] Bouanane stabbed six more people while yelling "Allahu akbar" and running towards Puutori, approximately 465 metres (1,526 ft) away.

[22][29][30] When police confronted Bouanane stabbing a victim at street address Brahenkatu 14 near Puutori, he ignored verbal orders and was immobilised with a single shot to the thigh and a taser at 16:05.

[33][34] The Italian citizen did not receive critical injuries while Hassan Zubier, a British paramedic living in Sweden, was injured four times as he tried to help a victim.

[35][36] Zubier, hailed as a hero by Finnish media, was open about the incident and appeared on national television to discuss it.

He stated that after he had rushed to treat a bleeding woman injured during the attack, Bouanane stabbed him several times.

Finnish Prime Minister Juha Sipilä tweeted on 18 August 2017, at 17:09: "The Government is closely following the events in Turku and the on-going police operation.

[47][48] Prime Minister Juha Sipilä commented on the need for intelligence gathering reform that "it should be obvious from a constitutional standpoint that the right to life is a more precious fundamental right than the right to privacy in light of the Turku event.

[50][51] Interior Minister Paula Risikko did not find the suggestion feasible—as the residents of such centres are not placed under constant surveillance, but are only required to check in regularly.

It was considered to be an illustration of the police officers' response during an exceptional event as well as a reminder of how important freedom of the press is.

[1][2] In December 2017, a Facebook fundraiser was launched to financially support Hassan Zubier who was injured while assisting another victim of the attack.

[53] On 25 June 2018, Zubier became the first foreign person to be awarded Finland's Life Saving Medal for helping a victim and protecting others during the attack.

[55] Zubier applied for Finnish state pension based on injuries he suffered during the attack, but admitted in August 2018 to benefits fraud by forging work history in his application.

[67] On the morning of 20 August, NBI conducted an approximately 45-minute re-enactment of the event at Market Square and Puutori as a normal method of investigating serious crimes.

[89] (As of September 2018, the wanted suspect had contacted NBI with the intent to clear the matter, but he had not been questioned nor was his exact location known.

[91][40] The fourth remanded accessory suspect was released from detention and cleared of charges on 1 September, leaving Bouanane as the only one remaining in custody.

[96] On 19 October, the Finnish Government established an independent inquiry team to investigate the stabbing and provide recommendations on how new attacks could be prevented.

[97] NBI held a press conference on 7 February 2018 to report that the investigation was concluded and the material, spanning some 1,400 pages, would be forwarded to the Finnish Prosecution Office.

[108] Prime Minister Juha Sipilä remarked during a press conference on 19 August 2017: "If the criminal charge is confirmed to be terror-related murder, that would be a first in Finland.