During the three successful attempts, he was only met with silence on the other end of the line as the dispatcher receiving the call left to respond to the shootings on Heumarkt.

[13] Upon arriving there, the gunman got out of the car and fatally shot Păun who was sitting in his vehicle, then entered a kiosk adjacent to the bar, where he killed three people.

A reconstruction of the shooting by Forensic Architecture later determined that those inside the bar would've had ample time to flee if the emergency exit was unlocked.

[20] The nine people killed by the attacker during the two shootings were identified as: four Germans Gökhan Gültekin (37), Ferhat Unvar (23), Mercedes Kierpacz (35), Said Nesar Hashemi (21) (two of whom had Kurdish origins, another of Sinti origins, and another with Afghan nationality), Sedat Gürbüz (29) and Fatih Saraçoğlu (34) two Turks, Hamza Kurtović (22) a Bosnian, Kaloyan Velkov (33) a Bulgarian, and Vili Viorel Păun (22) a Romanian.

[31][32] On his personal website, he published a racist manifesto and posted videos showing his political and misogynist beliefs, accused US President Donald Trump of stealing his slogans,[33] promoted extreme eugenics and expressed frustration that due to his psychological issues he could never experience an intimate relationship with a woman.

[34] Media outlets often described Rathjen as an incel or "involuntary celibate"; however, researcher Meredith L. Pruden and colleagues say he is more accurately characterized as an adherent of the male separatist Men Going Their Own Way.

[39] In the videos he recorded and his manifesto, Rathjen also talked about the "secret service" that stalks humanity and compared his actions to that of Edward Snowden.

[19] According to Germany's general prosecutor Peter Frank, Rathjen had contacted German authorities with his conspiracy theories three months before the attack: on 6 November 2019, Rathjen had written a letter to the Public Prosecutor General urging action against a "secret service" organisation, which he claimed was tapping into people's brains to control world events.

Parts of this 19-page letter were virtually identical to his 24-page manifesto published on his website in February 2020, but it was unclear whether it included any threats against ethnic minorities.

[42] Federal prosecutors are treating the attack as terrorism, with officials saying there is evidence the gunman was a far-right extremist, as well as signs of xenophobic motives for the killings.

[44] As a result of the shootings, German Chancellor Angela Merkel cancelled a planned trip to Halle and expressed her condolences to the victims' families.

[47] German president Frank-Walter Steinmeier, his wife Elke Büdenbender, and the Hesse minister-president Volker Bouffier attended a vigil at one of the shooting sites.

[48][49] Pope Francis extended his sympathy to the families who lost their loved ones during the shooting incident in Hanau, through the Vatican Secretary of State, Cardinal Pietro Parolin.

[54][55] On the one year anniversary of the attack (19 February 2021), large memorial services and rallies were held in multiple cities in Germany to commemorate the victims, warn against racism and demand further action.