## Facts

- Augusto Pinochet Ugarte, former head of state of Chile, traveled to the United Kingdom in October 1998 and was arrested on provisional warrants issued after Spain sought his extradition.
- Spain sought extradition to prosecute alleged torture, conspiracy to torture, hostage-taking, and related killings committed during Pinochet’s time in office.
- The Divisional Court quashed a warrant, holding that Pinochet had immunity as a former head of state under domestic statute and customary international law.
- A prior appellate decision allowing extradition to proceed was set aside for apparent bias, requiring a rehearing before a newly constituted seven-member appellate panel.
- The rehearing focused on (a) whether a former head of state could claim subject-matter immunity for alleged torture and related conduct; and (b) whether extradition was limited by domestic implementation dates and double criminality requirements.

## Issues

1. Whether a former head of state has immunity from arrest and extradition proceedings for alleged torture and conspiracy to torture committed while in office.
2. Whether, and for what time period, the alleged conduct could qualify as “extradition crimes” given double criminality and the United Kingdom’s implementation of universal jurisdiction for torture.
3. Whether non-torture charges (including related conspiracies and killings) could proceed insofar as they were connected to qualifying torture conduct.

## Decision

- The House of Lords allowed the appeals in part and held that Pinochet was not immune for acts of torture (and closely connected conspiracy to torture) committed after 8 December 1988, when the United Kingdom’s torture offense with universal jurisdiction took effect.
- For alleged conduct before 8 December 1988, extradition was barred because the relevant domestic offense basis was not in force, so double criminality was not satisfied.
- Extradition proceedings could continue only on a narrowed set of charges tied to post-8 December 1988 torture (and sufficiently connected conspiracy), not on the full range of historical allegations.
- The ruling confirmed that the executive had jurisdiction to consider extradition only within those limits.

## Legal Principles

- Head-of-state immunity distinguishes between personal immunity for incumbents and subject-matter immunity for official acts that may continue after leaving office.
- After a state implements obligations requiring criminalization and universal jurisdiction over torture, torture by state officials cannot be treated as an immune “official act” for subject-matter immunity purposes, at least for post-implementation conduct.
- Extradition depends on double criminality: the conduct must have been criminal under the law of both the requesting and requested states at the relevant time.
- Domestic implementing legislation can impose temporal limits on extradition for international crimes; courts may restrict extradition to the period when the implementing offense was in force.
- Ancillary or related charges may proceed only if they fit within the statutory extradition framework and are adequately anchored to qualifying extradition crimes.

## Conclusion

The House of Lords held that a former head of state could not rely on subject-matter immunity to block extradition for torture (and closely related conspiracy) occurring after the United Kingdom implemented universal jurisdiction for torture, while strictly limiting extradition to conduct satisfying double criminality and the implementation date constraint.


R v. Bow St. Metro. Stipendiary Magistrate ex rel. Pinochet Ugarte (No. 3), [2000] 1 A.C. 147 (H.L. 1999)