More details emerged Wednesday about the 20-year-old Islamic State supporter who killed four people in the heart of the Austrian capital before being shot dead by police.
After being convicted last year of attempting to travel to Syria to try to join IS, Kujtim Fejzulai "managed to fool the justice system's de-radicalisation programme, to fool the people in it, and to get an early release," Austrian Interior Minister Nehammer has said.
"There were no warning signs of his radicalisation," he added.
Fejzulai, whose name suggests he was of ethnic Albanian origin but held dual Austrian-Macedonian nationality, was sentenced to 22 months in prison in April last year but was released in December.
Justice Minister Alma Zadic said Fejzulai had been paroled after serving two-thirds of his sentence but also put on three years' probation.
"This enables us to continue to have an influence over the perpetrator beyond the term of their prison sentence," she said.
This would not have been the case had he simply served his full sentence, which normally would have expired in July 2020, she added.
In Fejzulai's case, he was required to report regularly to probation counsellors and the de-radicalisation programme DERAD, "which, according to our current knowledge, he did," Zadic said.
But a raid on his home after Monday's shooting showed that "the attacker, despite all the outward signs of having integrated into society, did exactly the opposite," Interior Minister Karl Nehammer said.
In a Facebook post, he posed with the shortened Kalashnikov and the machete he would go on to use in the attack together with a caption saying he was "serving the sultanate" and other typical IS messages, Nehammer said.
During his 2019 trial, Fejzulai said: "I wanted to leave home, I knew that (in Syria) there was a better life waiting for me, my own flat, my own money."
His lawyer Nikolaus Rast told AFP that "when I got to know him I'd say that he was a lost soul, who gave the impression that he was looking for his place in the world".
"No-one thought he would be capable of doing this, no-one could have had that kind of suspicion, and if we'd known we'd have intervened much sooner," Rast added.
Austrian authorities had already attempted once to strip Fejzulai -- who was born in the commuter town of Moedling south of Vienna -- of his Austrian citizenship.
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But this was not successful because "there was not enough evidence about his activities", Nehammer said.
It remains unclear where the attacker spent his childhood, and most recently he was living in social housing in a working-class area of northern Vienna.
Neighbour Goldana Nikolic told AFP that he was "totally unremarkable", giving no outward sign of Islamic radicalisation and saying that he helped "carry shopping bags".
Lawyer Rast said Fejzulai's mother led an "absolutely Western" lifestyle and had been "in despair" over the charges over his attempt to travel to Syria.
"I don't know what I did wrong. I didn't raise my child this way," he recalled her saying.
Rast told Der Standard newspaper that Fejzulai had begun attending a mosque in 2016 where he "stumbled on the wrong imam".
According to police in North Macedonia, a landlocked country in the Western Balkans, around 150 nationals travelled to fight alongside jihadists in Iraq and Syria, mainly between 2012 and 2016.
Most hailed from North Macedonia's ethnic Albanian Muslim minority, who make up around a quarter of the 2.1 million population.
Around half have returned, while many others with links to IS have since been imprisoned in jails in North Macedonia or other countries.
The Macedonian interior ministry said it had been asked to provide information on three people with both Austrian and Macedonian citizenship, including Fejzulai.
"We are intensively cooperating on all elements connected to this case," it said.
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