The powers of a police officer to arrest a person without a warrant in the ACT are governed by section 212 of the Crimes Act 1900 (ACT). The section provides that, only if the police officer suspects on reasonable grounds that a person has committed or is committing an offence, and proceeding by way of summons would be inappropriate, will the arrest be lawful. In theory, the two-limb test is a safeguard for a person’s common law right to liberty. In practice, the threshold requirement of ‘suspects on reasonable grounds’ is often overlooked.

What are ‘reasonable grounds’ for suspicion?

Similar provisions to the ACT are included in section 99 of the Law Enforcement (Powers and Responsibilities) Act 2002 (NSW), which also requires police officers to suspect on reasonable grounds an offence is or has been committed for an arrest without warrant to be lawful.

The frequently cited High Court decision of George v Rockett (1990) 170 CLR 104 held that reasonable suspicion must be formed on the ‘existence of facts which are sufficient to induce that state of mind in a reasonable person.’ This objective requirement was further refined in the more recent decision of Prior v Mole [2017] HCA 10, where the High Court issued cautionary remarks about a suspicion being based on a police officer’s subjective prejudice (at [71]). These cases show that for an arrest to be lawful, there must be objective facts to suggest that an offence has or is being committed at the time of the arrest. This can be contrasted with a situation where a police officer arrests a person because of their criminal history, race, age, appearance or the like. The cases pose a fundamental question for determination – what objective facts were available to police when the arrest was made? If these facts would not lead a reasonable person to suspect an offence has or is being committed, it is unlikely the arrest was lawful.

When will summons be inappropriate?

The second requirement that an arrest without a warrant will only be lawful where summons is not appropriate is an additional requirement police must comply with. It supports the common law position that arrest ought to be a measure of last resort. A ‘summons’ in this context is a legal document that orders an individual to appear before a court at a specific date and time in relation to a criminal charge.  In the ACT, a police officer must be satisfied that a summons would not achieve one or more of the following purposes before an arrest can be made:

1. Ensuring the person appears at court;
2. Preventing repetition or continuation of the offence or other offences;
3. Preventing the concealment, loss or destruction of evidence;
4. Preventing harassment of, or interference with anyone who may provide evidence;
5. Preventing the fabrication of evidence; or
6. Preserving the safety or welfare of the person.

In reality, the power to arrest without warrant is frequently relied upon by police. The deprivation of one’s liberty is an extreme power to exercise, and leaving police’s ability to do so unchecked has consequences not only for the subject of an arrest, but also the admissibility of evidence acquired as a result. This elevates the need for ongoing awareness about the limited circumstances in which arrest without a warrant will be lawful, and the importance of scrutinising the exercise of police powers.

If you or someone you know has been arrested and needs advice, contact one of our highly experienced criminal lawyers at info@codalaw.com.au.