In the aftermath of such events, there are the questions we ask ourselves, the questions we ask each other, and the questions for our intelligence agencies and police. Just as every aspect of an attacker’s life is dissected for public consumption, so too are the actions of security agencies and police.

What did they know about the perpetrator? If they had information to suggest an offender posed a risk, why wasn’t more done? Often, it doesn’t take long for the questions to morph into something that sounds a lot like a blame game.

The terrorism attack in Melbourne by Hassan Khalif Shire Ali on Friday left one man dead, and resulted in serious injury to two other innocent parties. Ali drove a vehicle loaded with gas bottles into the city centre, and ignited the vehicle into a ball of flames before he stabbed three people.

His attempts to then stab the police officers who were attempting to subdue him are well documented by the many witnesses who took footage on their mobile phones. 

What we all now know is that Hassan Khalif Shire Ali was known to security agencies. His passport had been cancelled because he wanted to fight with IS in Syria, but he was not considered to be a violent threat at home. In hindsight, we could all call that a mistake but as Australian Federal Police assistant commissioner for terrorism Ian McCartney said, “this is a complex and challenging business”. “From flash to bang for some of these people is pretty short,” as Rodger Shanahan, a terrorism analyst put it.

We will continue to seek answers and to learn lessons from this latest incident, because we must. In the meantime, the actions of the officers at the scene – and the few Good Samaritans who came to help – deserve our commendation. The officer who shot and killed Ali had been in the job for just three months. 

We sadly must accept that only in a perfect world can every act of terrorism be stopped. But let us not forget the valour of those who would risk their lives trying to protect us.