Effecting an arrest

There are no particular words that must be used when police arrest someone, but they must make it clear that the person is under arrest and is not free to leave.

An invitation to attend a police station and answer questions is voluntary unless the person has been arrested. A person who refuses to go with the police may be arrested and charged, and taken into custody, only if the police reasonably suspect that person of committing or having committed an offence, or of being about to commit an offence [Summary Offences Act 1953 (SA) s 75]. Otherwise the police cannot lawfully detain the person. Police should make it clear to the person they are questioning if they are free to leave at any time.

Use of reasonable force

A police officer may use as much force as is reasonably necessary to effect an arrest. Unreasonable force is assault. Where there is a dispute as to the reasonableness of the force used, it will be up to the court to decide whether the force used was reasonable in the circumstances. A person who believes unreasonable force is used against them may consider making a complaint directly to the police or to the Office for Public Integrity.

Handcuffs or a similar restraint are usually considered reasonable where the person has physically resisted arrest or attempted to run away.

It is an offence for a police officer to place a spit hood on a person's head, with a maximum penalty of imprisonment for 2 years [Summary Offences Act 1953 (SA) s 82A]. A spit hood is a covering that is intended to be placed over a person's head to prevent the person from spitting on, or biting, another person.

Hindering and resisting arrest

It is an offence to resist or hinder a police officer in the execution of their duty – including the making of a lawful arrest [Summary Offences Act 1953 (SA) s 6]. Both hindering and resisting involve a conscious and voluntary act on the part of the person concerned. The person concerned must have realised that their actions frustrated the police in performing their duty.

Hindering does not require physical interference, although it can involve this (such as physically preventing police from lawfully entering a property to speak to an occupant). It can include behaviour such as constant and unwarranted interrupting of police while they are attempting to question another person, or acting as a ‘lookout’ to warn others of a police presence.

Resistance also requires some kind of positive action designed to defeat police in performing their duties. Although it most commonly involves physical force by the person being arrested, it may be constituted by passive resistance techniques such as those commonly employed in civil protests (such as sitting or lying down, linking arms with others and becoming inert and refusing to cooperate).

Where direct force is used to resist arrest, the likelihood of a police officer being assaulted during the process is high. Assaulting a police officer during the course of their duties is a serious offence attracting heavy penalties under s 6 of the Summary Offences Act 1953 (SA) and ss 20 and 20AA of the Criminal Law Consolidation Act 1935 (SA).

Generally an arrest will be lawful if the police officer who carries it out has reasonable cause to suspect an offence has occurred or will occur. The arresting officer may be mistaken as to the facts, in which case the person will be later released. Provided the officer had an honest and reasonable belief in the relevant facts, then they have acted lawfully. For that reason, no attempt should ever be made to resist arrest.

A person who is wrongfully arrested should seek legal advice before considering options such as taking civil action for damages or compensation or making a complaint to the Office for Public Integrity.