Mirsad O., 34, known by the Islamic name of 'Ebu Tejma', was arrested in November 2014 at the council flat he shared with his pregnant wife and five children.
Vienna's elite heavily-armed counter-terrorism unit the WEGA (Wiener Einsatzgruppe Alarmabteilung), which carried out the raid, also recovered a fortune in jewellery, cash and savings books. He had also been spotted driving top-of-the-range sport cars when he was under surveillance.
At the time it was reported that he was responsible for the radicalisation of two young girls, Samra Kesinovic, 17, and her friend Sabina Selimovic, who was 15 when they left to join Isis in Syria in April 2014.
They became the terror organisation's latest PR coup when they turned out to be poster girls for the death cult, and featured on Isis websites carrying AK-47s and surrounded by groups of armed men.
Neither however has been seen for almost a year, with a Tunisian Isis returnee telling investigators that Samra had been forced to become a sex slave who was offered as a present to new fighters, and that she was later stoned to death when she tried to escape.
A United Nations official revealed a girl "of Bosnian origin from Austria" - believed to be Sabina - had died fighting in Syria.
Both had allegedly become radicalised by Mirsad O., an Islamic preacher originally from Bosnia who is now on trial in the southern city of Graz. When they had left their homes, they left a note for their families which read: "Don't look for us. We will serve Allah and we will die for him."
'Like a popstar'
Mirsad O. has also been linked with the recruitment of more than 160 others who eventually joined Isis. The valuables that were seized at his home had all been provided by Muslims radicalised by the preacher and his cronies in a network that reportedly extended across the country and into the rest of Europe.
The prosecutor also said that a file had been found on his computer that was a guide to making an explosive device that could be detonated by mobile phone.
His arrest was seen as a major blow against the terrorist group's activities and now the trial under judge Stephan Mertens is taking place in part behind closed doors to protect the identity of witnesses.
It is the first time a Muslim has been charged with murder through terrorism in Austria and he is also accused of inciting a co-accused in the murder of "infidels" which could result in up to 20 years in prison.
The co-accused is a 28-year-old Russian who was targeted by police, not because of his preaching, but rather because of his violence as Mirsad O.'s right-hand man. He is accused of carrying out numerous murders of civilians in Syria as well as the shooting of sex slaves and forcing others out of their homes.
Opening the case, the prosecutor told the court that Mirsad O.'s "main message was that Islam needed to be spread to the world through jihad." He added that he was travelling through Europe "like a popstar on tour".
He added that the popstar analogy was particularly appropriate because Mirsad O. even had his own YouTube channel aimed at young Muslims aged between 14 and their late twenties. The prosecutor said it aimed "to carry out brainwashing on those that viewed it".
Security service insiders claim that he was not only one of 200 leading jihadists, but was also one of the leaders of the so called 'Bosnian cell' based in the Meidling district of Vienna that was "one of the most important logistic and financial support centres for jihadist activities in Europe", according to the 'Vecernje novosti', a local newspaper in Bosnia and Herzegovina.
Austria has been concerned for years over fears that the country was becoming a hub for terrorist activities after inviting thousands of Muslim refugees into the country during the breakup of the former Yugoslavia.
It meant Vienna provided a fertile breeding ground for Mirsad O. and his network. The Austrian newspaper the Krone claimed that "there was scarcely a single recruit in Europe for jihad in which he and his group were not involved". In preparing the case, the prosecutor also asked German Islam expert Guido Steinberg to analyse YouTube videos that Mirsad O. had made.
Originally from the small Serbian town of Tutin, Mirsad O. was known in Bosnia and Herzegovina as a preacher of hatred and intolerance, who very soon found himself allied with the extreme form of Islam known as Wahhabism - an ultra-conservative, Saudi brand of Salafism.
His arrest followed two years of investigation by intelligence officials who had been tapping his communications, monitoring his phone calls and building up a picture of his network.
One of those connections is allegedly a direct line to the caliph of Isis terrorism, Abu Bakr al-Baghdadi.
Security services recorded a constant stream of Salafist preachers, often accompanied by fighters travelling up from Bosnia and Herzegovina, to Mirsad O.'s mosque and the imam appeared in online videos saying that it is every Muslim's duty to join jihad if an Islamic state is under attack from non-believers.
Lawyers for Mirsad O. told the court that he would claim to have done nothing more than teach Islam, as he had been trained to do so in Saudi Arabia.
Opening the case, the prosecutor in Graz said that there were "so many already from Austria, young men and women who went to Syria and have been killed".
"The Isis ideology is an enormous danger to our society that needs to be seriously tackled," he added.
Story courtesy of Central European News.