Questioning and surveillance


When the Gardaí are investigating and detecting crime they are entitled to observe the actions of any individual. However, the Gardaí must act in accordance with the law when questioning members of the public. To do this, the Gardaí are given certain powers to stop and question the public.

Where a Garda is investigating a criminal offence, the Garda is entitled to seek the co-operation of anyone by asking the person questions about what they saw or heard. However, while the Gardaí are entitled to question members of the public, there is generally no legal obligation to answer any such questions or to co-operate with the Gardaí.


Common law powers

Most of the powers given to the Gardaí to stop and question members of the public are set out in legislation (known as statutory powers). However, there are a number of instances where a Garda is entitled to stop and question you where no statutory power exists. This is known as a common law power.

An example of this would be where a Garda observes you acting suspiciously late at night in an area where a lot of crimes are being committed. The Garda is entitled to stop you in order to detect and prevent crime. You are under no legal obligation to co-operate with the Garda and the Garda cannot use force to restrain your freedom under common law, short of arresting you.

However, if the Garda has reasonable grounds for suspecting that you committed an offence, the Garda can use a statutory power to demand your name and address. If you refuse to provide them, then the Garda can arrest you.

The Gardaí have a common law power to stop motorists at random in order to detect and prevent crime. This power can be used, for example, to stop cars near pubs to identify drunk drivers or in order to check cars passing through an area where a lot of crime had been committed.

Statutory powers

As outlined above, a Garda is entitled to stop a motorist under common law for the purpose of detecting and preventing crime. The Garda is also entitled to stop a motorist under a statutory power given under Section 109 of the Road Traffic Act 1961, which obliges a motorist to stop their vehicle when required to do so by a Garda. This statutory power is given to the Gardaí for the purpose of inspecting vehicle tax, insurance certificates, driving licenses and road worthiness of vehicles. Unlike common law power, it is confined to road traffic offences.

There are numerous statutory provisions which allow the Gardaí to stop someone for certain purposes. However, the only statutory provision which specifically permits a Garda to stop and question someone, short of arresting the person, is section 30 of the Offences Against the State Act 1939.

Section 30 allows a Garda to stop and interrogate anyone whom the Garda suspects of having committed or being about to commit an offence under the 1939 Act or an offence scheduled for the purposes of the Act. (There are a number of offences listed as being scheduled offences, such as, firearms offences and explosive offences). This gives the Gardaí the power to stop a suspect in a public place. It also gives them the power to stop any vehicle, or any ship, boat or other vessel for the purposes of questioning and searching, and if necessary, arresting the suspect.


It is commonplace for the Gardaí to use surveillance on people and locations in their efforts to detect and prevent crime. Surveillance is used in a number of situations.

If, for example, you are suspected of being involved in criminal activities you may be placed under surveillance. Similarly, when the Gardaí have information that a crime is to be committed at a certain location they may decide to place that premises or location under surveillance. The decision to place a person or premises under surveillance is primarily one for the Gardaí but must be made within the law.

Everyone in Ireland enjoys a general freedom to observe the movements of others and, indeed, to observe the property of others. While this is true, the manner of such observations cannot be such as to cause alarm or distress to another person.

Section 10 of the Non-fatal Offences Against the Persons Act 1997 protects you from being stalked or harassed. While such protection exists, it is unlikely that this protection could be used to stop Garda surveillance since you would not normally be aware that the Gardaí have you under surveillance.

Another protection you have with regard to surveillance is the constitutional right to privacy which is a fundamental right of everyone. The possible breach of this right to privacy relates to surveillance being carried out by neighbours, husbands or wives, private investigators or stalkers.

Similar protections from unjustified surveillance arise under the General Data Protection Regulation. However, the courts have not shown any willingness to use these protections in cases where the surveillance was being conducted by the Gardaí in the investigation, detection and prevention of specific crimes.

The Criminal Justice (Surveillance) Act 2009 provides a statutory framework for evidence obtained by secret surveillance. It is intended that such surveillance be used to combat serious criminal, subversive or terrorist activity. The Act provides for a judicial authorisation procedure for surveillance and a complaints procedure.

Interception of phone calls and packages

Under the Interception of Postal Packets and Telecommunications Messages (Regulation) Act 1993 there are statutory provisions which give the Gardaí the power to use technology for the purpose of keeping people under surveillance. An example of this is the power given to the Gardaí to intercept a telephone call for the purpose of investigating criminal offences. This power is granted by the Minister for Justice and Equality.

The Minister may also authorise the interception and opening of postal letters and packages. Only the Garda Commissioner can apply for such authorisation in relation to criminal offences. The Garda Commissioner and the Chief of Staff of the Defence Forces (Army) can apply for authorisation in relation to state security.

The operation of these intercepts is monitored by a judge of the High Court who is responsible for ensuring the intercepts are confined to those which are authorised by the Minister.

It is a criminal offence for someone to intercept a telephone call, letter or package addressed to someone else, without legal authorisation.

Page edited: 25 May 2020