Arrest is not simply an act; it is a legal state of detention. If it is carried out unlawfully, then issues of false imprisonment and assault by a police officer may arise.
Whether detention by police is for a brief period on a footpath or for several hours in a police station, you need to be aware that it is in fact a form of imprisonment, either lawful or unlawful.
When can police place you under arrest?
Broadly speaking, there are two ways in which police can place a person under arrest:
Arrest with a warrant; or
Arrest without a warrant.
Arrest with a warrant
Under the Police Powers and Responsibilities Act 2000 (“PPRA”), a police officer may apply to a Justice for a warrant to arrest a person for an offence (s369). The application must be sworn and state the grounds on which the warrant is sought.
The Justice may only issue an arrest warrant if they are satisfied that there are reasonable grounds for suspecting (s371):
that the person has committed the offence; and
for an offence other than an indictable offence, proceedings by way of complaint and summons or notice to appear for the offence would be ineffective, including because the person can not currently be located or served with a complaint and summons or notice to appear for the offence.
An arrest warrant must state the following (s372):
the name of the applicant for the warrant and the applicant's rank, registered number and station;
that any police officer may arrest the person named in the warrant;
the offence the person is alleged to have committed.
Once issued, it is lawful for any police officer acting under a warrant to arrest the person named in the warrant. In these circumstances, arrest includes apprehend, take into custody, detain, and remove to another place for examination or treatment (s369).
Arrest without a warrant
In practice, it is often impractical for a police officer to apply to a Justice for a warrant to arrest a person suspected of committing a crime. Because of this, many arrests occur without a warrant either at the scene of the crime or throughout the course of a police investigation.
Generally speaking, the PPRA provides that a police officer may arrest a person without a warrant if they hold a reasonable suspicion a person has committed or is committing an offence (s365). The grounds that must be satisfied to perform an arrest without a warrant are very broad and apply to both simple and indictable offences.
Example: If you were found in possession of drugs (i.e. Ecstasy, marijuana, and cocaine) outside a nightclub, this would provide a police officer with a reasonable suspicion of an offence having been committed and to place you under arrest without a warrant.
It is also lawful for a police officer without warrant, to arrest a person the police officer reasonably suspects has committed or is committing an indictable offence, for questioning the person about the offence, or investigating the offence (s365). Though this only applies to indictable offences, it provides police with broad powers to arrest and detain without charge.
As soon as practicable after arrest, a police officer must inform the person that they are under arrest and the nature of the alleged offence (s391).
If at any stage after arrest, a police officer considers there is insufficient evidence to maintain the charge, the officer has a duty to release the person (s376).
An arrest is a serious infringement upon a person’s liberty and should be avoided wherever possible. There is provision under the PPRA for police to issue a person with a Notice to Appear instead of placing them under arrest (s382-389). A Notice to Appear is an obligation for a person to appear in court on a specified date. It is far more preferable for a person to be issued with a Notice to Appear, as it does not require them to be arrested and detained in police custody for any period of time. The decision to issue a Notice to Appear is entirely at the police officer’s discretion.