The government still needs to demonstrate that indefinite detention for terrorists is necessary

On Friday, Prime Minister Malcolm Turnbull secured state and territory backing for a post-sentence detention regime for convicted terrorists.

The regime would be modelled on existing laws for high-risk sex and violent offenders. But has the government made the case for its introduction?

Post-sentence regimes

In 2003, Queensland became the first Australian jurisdiction to introduce post-sentence preventive detention and supervision orders for serious sex offenders.

Queensland’s Supreme Court is empowered to make a preventive detention or supervision order where satisfied to a high degree of probability that the offender poses a “serious danger to the community” – that is, where there “is an unacceptable risk that the prisoner will commit a serious sexual offence” if an order is not made.

A supervision order imposes obligations on an offender when released from custody. These may include electronic tagging, reporting to corrective services and not residing in specific locations. A continuing detention order requires a person to remain in custody at the completion of a term of imprisonment.

The Queensland regime has withstood constitutional challenge. The High Court held that the powers conferred on the Supreme Court were not incompatible with that court’s exercise of federal jurisdiction under Chapter III of the Constitution.

This decision green-lit the introduction of similar regimes in Victoria, Western Australia, New South Wales, the Northern Territory and South Australia. In 2013, NSW became the first Australian jurisdiction to extend its legislative scheme beyond serious sex offenders to a new category of offender: high-risk violent offenders. South Australia followed suit in 2015.

Controversially, these regimes enable indefinite detention or supervision at the end of a term of imprisonment. This has given rise to concerns about procedural fairness, proportionality and finality in sentencing, and double punishment.

In NSW, a court may make an extended supervision order for a term of up to five years. The court may make subsequent extended supervision orders against the same offender. It is an offence to fail to comply with the requirements of a supervision order. This is punishable by five years’ imprisonment or a fine – or both.

A continuing detention order may be made for a term of up to five years. Subsequent continuing detention orders may be made against the same offender. The effect of this is that an offender may be detained indefinitely.

The terrorism context

A version of the high-risk offender post-sentence supervision regime has already been implemented for those convicted of terrorism-related offences. The Foreign Fighters Act extended the existing system of control orders to individuals who have been convicted of a terrorism-related offence.

On completion of a sentence, offenders could find themselves subject to an order imposing conditions similar to those available for use against sex offenders under extended supervision orders, such as electronic tagging, curfews and requirements to report to the police.

The UK has a similar but less restrictive system. Persons convicted of terrorism offences or offences having a terrorist connection may be subject to notification requirements at the end of their sentence. These include obligations to notify the police of certain information on an annual basis and of any changes – including their name, date of birth, national insurance number, plans to travel abroad and any addresses at which they live or regularly reside.

It is an offence punishable by a maximum five years’ imprisonment or a fine (or both) to fail to comply with the notification requirements.

These regimes are not uncontroversial. But the proposal to create a preventive detention regime for those convicted of terrorism offences is of real concern.

High-risk sex and violent offenders subject to post-sentence preventive detention have committed serious offences, or have attempted or conspired to commit such offences. These include sexual offences involving violence or children, and violent offences causing death or grievous bodily harm.

In NSW, the high-risk violent offender provisions would already apply to a person who conspired, attempted or engaged in an act of terrorism that caused death or grievous bodily harm.

To date, no-one has been convicted in Australia of the most serious terrorist offence – engaging in a terrorist act. Instead, those imprisoned for terrorist offences have, for the most part, been convicted of attempting or conspiring to do an act in preparation for a terrorist act.

Preparatory offences criminalise behaviour long in advance of the actual commission of a terrorist act, such as obtaining a price list on chemicals, and long before any harm has occurred.

The potentially deadly consequences of planning or preparing for a terrorist attack cannot be ignored. But detaining indefinitely a person who may have committed only relatively minor offences is disproportionate, and in stark contrast to the sex offender regimes.

Are post-sentence regimes justified?

A terrorist attack on Australian soil, akin to the recent attacks in Paris, would be catastrophic. It is right that police and intelligence agencies have the necessary powers to prevent that from occurring. But it is questionable whether post-sentence preventive detention is the best means to achieve that end.

An Australian study into the use of post-sentence regimes for serious sex offenders highlights concerns about the increased risks they create. These include that:

• they target only known offenders and do not reduce recidivism;

• the community falsely believes they are protected from sex offenders; and

• the regime increases offenders’ anger and dissatisfaction.

If the same risks emerge in the terrorism context, then the use of post-sentence preventive detention may be counter-productive, not least if it makes the community feel more secure while simultaneously increasing offenders’ anger and dissatisfaction. If released, that anger could manifest itself in serious harm to the Australian public.

Detaining persons convicted of terrorist offences for lengthy periods after they have served their time could risk radicalising a section of the community who see the measure as unjust.

The government’s aim with these measures is valid. It wants to prevent those who have served sentences for terrorist crimes but who have not rehabilitated from being released into the community where they could engage in future acts of terrorist violence.

But before it introduces what will be the sixth tranche of anti-terrorism laws in the past two years, the onus is on the government to demonstrate that the measures are necessary, proportionate and will make us more – not less – secure.