A police officer can stop, search and detain vehicles, vessels (ships and boats) and people without a search warrant where there is reasonable cause to suspect the presence of stolen goods, possession of an object constituting an offence, or there is evidence of an indictable offence [see Summary Offences Act 1953 (SA) s 68(1)(a) for vehicles and vessels; Summary Offences Act 1953 (SA) s 68(1)(b) for people; Summary Offences Act 1953 (SA) s 69 for power to board vessels; Summary Offences Act 1953 (SA) s 70 for power to stop and search vessels; Summary Offences Act 1953 (SA) s 71 for arrest of person(s) committing an offence on board ships].

A police officer can enter land or premises to search for and examine vehicle(s) suspected of having been stolen or used without the consent of the owner [see Summary Offences Act 1953 (SA) s 68A].

A police officer can apprehend any person found to be drunk and behaving in a riotous or indecent manner, or whom the police officer finds fighting, or using threatening, abusive or insulting words, or behaving in a threatening, abusive or insulting manner [see Summary Offences Act 1953 (SA) s 74(1)].

A police officer may enter a public venue, order people behaving in a disorderly manner to leave, and use reasonable force to remove them [see Summary Offences Act 1953 (SA) s 73(1)].

Under the Liquor Licensing Act 1997 (SA), a police officer can ask for proof of age and use reasonable force to evict a person under 18 years [see s 115 for proof of age; s 116 for reasonable force].

Under the Public Intoxication Act 1984 (SA), a police officer can apprehend a person who is unable to take proper care of themselves due to the influence of alcohol or drugs, using reasonable force if necessary, and search the person for any items which may be a danger to themselves or other people [see s 7].

Where there is reasonable cause to suspect a person has committed, is committing, or is about to commit an offence, or where a person may be able to assist with the investigation of an offence, that person must provide their name and other personal details as requested by a police officer [see Summary Offences Act 1953 (SA) s 74A(1)].

That person must also provide evidence to support their personal details if requested by the police officer [see s 74A(2) ] It is an offence to refuse to provide the requested information, or to provide false or misleading information [ s 74A(3); see also Right to Silence (below)].

Personal details include the person’s full name, date of birth, residential and business addresses [see s 74A(5) ]. A police officer must identify him or herself and produce their police identification or state their surname, rank and identification number if that information is requested by the person from whom the officer requires the personal information [see s 74A(4)].

A police officer may ask questions about the identity of the driver and owner of a vehicle at a particular time or on a particular occasion [see Summary Offences Act 1953 (SA) s 74AB(1)]. It is an offence to refuse or to provide false or misleading information [see Summary Offences Act 1953 (SA) s 74AB(2); see also Right to Silence (below)]. A police officer must identify him or herself and produce their police identification or state their surname, rank and identification number if that information is requested by the person from whom the officer requires the information [see Summary Offences Act 1953 (SA) s 74AB(3)].

A police officer may ask questions in relation to firearms or firearms related items (including ammunition) to identify the owner, and to identify other persons who have had possession of the firearm [see Firearms Act 2015 (SA ss 55, 56, 57]. It is an offence to refuse or fail to comply with providing such information, with a maximum penalty of $20,000 or 4 years imprisonment [s 55(5)].