Declan is in remission from leukaemia and recently spent the day with Australia's Federal Police.
He was collected from home in a motorcade, taken to the specialist response group headquarters where he took part in a hostage scenario.
Declan's parents say the experience gave the family something other than his treatment to focus on.
"He has been telling all our friends and family that he is going to blow stuff up and I think they've been really jealous of that," says his mum Belinda.
"He wanted to just blow something up and he did that, which was awesome."