To clarify the hypothesis of the presence of a second assailant in the attack in Vienna, which killed at least 4 people on Monday evening, the police resorted to a technique that was at the very least singular.
The security forces in the capital have asked the population for help.
It is a very original investigative technique.
While at least one man killed four people in Monday night shootings in central Vienna, Austria, doubts remained about the existence of a possible second assailant.
To remove it as much as possible, the Austrian police resorted to a new method: asking the Viennese population to send them all the videos and photos taken during the nine minutes that the attack lasted.
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20,000 videos sent by the Austrians to the police
In a few hours, therefore, around 20,000 videos were sent by the Austrians on a specially set up digital platform.
The shootings that broke out at six locations in the Austrian capital were filmed from different angles by residents who had taken cover.
But despite the large number of images, at no time did a possible second assailant appear.
An attacker who "cheated" the deradicalization program
This is why the investigation into this attack, claimed by the Islamic State early in the evening Tuesday, focuses on the 20-year-old assailant who was shot dead by the police.
Born in the suburbs of Vienna, he was sentenced to 22 months in prison in 2019 for trying to join Syria.
Passed through the Austrian deradicalization program, he managed to deceive everyone, keeping in touch with German jihadists he met on the border between Turkey and Syria.
For the time being, the Austrian security forces have carried out 14 arrests and 18 searches as part of this investigation.
In addition, two young Swiss men aged 18 and 24 were arrested on Tuesday in Winterthur, near Zurich, in northern Switzerland.