The level of a*se covering and victim blaming in this entire scenario is absolutely mind-boggling. That might have been the AFP's line, but an independent magistrate certainly wasn't buying it.According to the AFP, they tried other means and this was a last resort. I don't know if it's justified or not but I can imagine the reasonable outrage if the kid later killed somebody, his history was revealed, and it was revealed the AFP didn't do all they could to stop him. I think they were in an extremely difficult situation.
It is not an "extremely difficult situation" to determine whether or not to deliberately entrap a 13-year old autistic child, it's just not.