Sections 101.1 of the Commonwealth Criminal Code states:

(1) A person commits an offence if the person engages in a terrorist act.

(2) Section 15.4 (extended geographical jurisdiction-category D) applies to an offence against subsection (1)

Section 15.4 states

If a law of the Commonwealth provides that this section applies to a particular offence, the offence applies:

(a) whether or not the conduct constituting the alleged offence occurs in Australia; and

(b) whether or not a result of the conduct constituting the alleged offence occurs in Australia.

In order for the Police to prove their case at Court, they must prove each of the following matters beyond a reasonable doubt.

The accused engaged in a terrorist act.

Possible defences to this offence include but are not limited to

1. The accused did not engage in a terrorist act.

2. The act was not terrorism.

3. Identification i.e. it was not the accused

This matter is Commonwealth Offence which means it is dealt with in the Supreme Court.