What it does
Mechanically, the instrument does three things. First, it makes a short set of Regulations under the Extradition Act 1988: the Extradition (United Mexican States) Regulations (reg 1). Second, it declares the United Mexican States (Mexico) to be an extradition country (reg 4). Third, it makes the Extradition Act 1988 apply in relation to Mexico subject to the bilateral Treaty on Extradition between Australia and Mexico done at Canberra on 22 June 1990, the full English text of which is set out in the Schedule (reg 5). The Regulations commence on 27 March 1991 (reg 2) and were made by the Governor‑General on the advice of the Federal Executive Council on 21 March 1991.
The Schedule is the operative treaty text. The treaty opens with a stated purpose claim by the Parties, that they are "aware of the close ties" between their peoples and "desiring to promote greater co‑operation" including "the suppression of crime". That is the Parties’ declared object; the mechanics of the instrument implement that object by bringing Mexico within the framework of Australia’s Extradition Act while specifying the detailed bilateral procedures and limits that govern requests between the two States (reg 5; Treaty, Preamble and Articles).
Key mechanical effects to note up front, all as set out in the Schedule: the treaty defines which offences are extraditable (Article 2); it lists exclusions and bars to extradition including political offences, nationality, statute of limitations, special tribunals and other grounds (Articles 5-14); it prescribes documentary and authentication requirements for requests (Articles 15-17); it creates provisional arrest procedures and time limits (Article 19); it sets rules for surrender, timeframes and release if removal does not occur within 60 days (Article 21); it establishes the rule of speciality , restricting subsequent prosecution for offences other than those for which extradition was granted, with explained exceptions (Article 18); it allocates certain costs between the Parties (Article 27); and it deals with transit, property, multilateral obligations and entry into force and termination (Articles 23-28). These treaty terms operate as the modifying text under which the Extradition Act will be applied in Australia in cases involving Mexico (reg 5).