In the trial surrounding the November 2020 terror attack in Vienna, two defendants were sentenced to life imprisonment for murder as supporters of the perpetrator.
Two other defendants received 19 and 20 years in prison in the Vienna district court on Thursday night.
The jury found it established that the four men had assisted in choosing the target for the attack and in obtaining firearms and ammunition.
The 20-year-old perpetrator was a sympathizer of the terrorist militia "Islamic State" (IS).
He killed four people in Vienna city center on November 2, 2020 before being shot dead by police.
One of the fatalities was a German art student who worked as a waitress in the popular nightlife district.
23 passers-by were injured, some seriously, including some Germans.
Members of extremist chat forums
The public prosecutor had also accused two other men of having contributed to the murder by preparing the assassination.
However, the jury acquitted her of this main charge due to lack of evidence.
But they were each sentenced to two years in prison for spreading Islamist terror propaganda.
Some of the sentences were suspended.
The judgments are not yet final.
According to prosecutors, most of the six suspects, aged between 22 and 32, were active members of extremist chat forums.
The assassin and one of the accused had been convicted before the assassination attempt because they had tried to travel to Syria and join IS fighters there.
Both were released early from prison in late 2019.
The young men in the dock distanced themselves from the assassin again on Wednesday before the verdict was announced.
They denied close contact with him and insisted that they were not terrorist sympathizers.
"For me it was a heinous act that cannot be justified in any way," said a 23-year-old defendant.
He had driven the later perpetrator to the Slovakian capital of Bratislava, where he tried unsuccessfully to buy ammunition.
He didn't realize what the perpetrator was planning.
"I distance myself from any terrorist group," he said.
This defendant was eventually acquitted of the charge of murder.
The investigative mishaps in the months leading up to the attack were not a central issue at the trial.
In early 2021, a commission of inquiry from the Ministry of the Interior criticized in a report that the Office for the Protection of the Constitution knew about the renewed radicalization of the perpetrator and the attempted purchase of ammunition in Bratislava, but still did not inform the public prosecutor.
As a consequence of the mistakes made by the authorities, the Austrian state security system was reformed and de-radicalization measures in prisons improved.