2. What we do now is the perpetrator was well-known to state and commonwealth authorities. He had a long history of violent crime infatuation which is extremism and mental instability. 

 

3. We know that he sent offensive letters to the families of Australian soldiers killed in Afghanistan and was found guilty of offenses related to this. 

 

4. We also know that he posted his graphic extremist material online. As the siege unfolded Yesterday, he sought to cloak his actions with the symbolism of the ISIL death cult.