[5][6] The attacker was 29-year-old Chérif Chekatt, who had multiple criminal convictions and was on a security services watchlist as a suspected Islamist extremist.

[10] In 2016, several people were arrested in Marseille and Strasbourg for planning a terrorist attack; officials considered cancelling the Christmas market, but it was ultimately held as scheduled.

[11] On the morning of 11 December 2018, the police raided the home of Chérif Chekatt in Neudorf with the intention of arresting him on suspicion of attempted murder.

[3][8][18] A 45-year-old Thai tourist[3] was hit in the head in front of a restaurant and died, despite a passersby attempting to resuscitate him; ambulances took over 45 minutes to arrive.

[8][12] Chekatt then escaped in the direction of Neudorf and Place de l'Étoile, taking a taxi cab; the driver was unharmed and reported to the police having taken an armed and wounded man.

[3] His testimony allowed the police to identify the gunman, as the man bragged about killing people and having a grenade at home.

[3] Five thousand people were stranded in a sports facility used as temporary shelter, and the European Parliament was put on lockdown.

[38][39][40] The perpetrator was Chérif Chekatt (French pronunciation: [ʃɛʁif ʃɛkat]),[15][42][43] a 29-year-old man born of a retired national French-Algerian delivery driver,[41][44] characterised as a "hardened criminal" who "converted to rigorous Islam".

[49] French police considered him a "gangster-jihadist", a term referring to people convicted of various crimes and "radicalised" in prison.

[59] He told fellow inmates in 2015 that he would "commit a robbery before departing for Syria or die a martyr",[60][61] and became "very interested in seeking weapons", according to a friend of the jihadist, Audrey Mondjehi.

[8] Four people close to Chekatt were detained for questioning after the shooting,[19] namely his father, who is tagged with a fiche "S" as well because of his religious fundamentalism,[63] his mother, and two of his brothers, both known for their local Salafist affiliation,[64] and a fifth person was taken into custody on 13 December.

[24][70][71] On the evening of 13 December, police found Chekatt in Strasbourg between Neudorf and the Stade de la Meinau.

[77] Nine days after Chekatt's death, a USB key containing a video of him pledging allegiance to the Islamic State was found among his belongings, judicial sources said.

[78][79] The leader of the Rassemblement National (RN) party, Marine Le Pen, described the attack as an "Islamist massacre".