Extradition of International Clients: How It Is Defended

When a person with ties in several countries becomes the subject of a surrender request, what is at stake is not just one more procedure, but their freedom of movement and, often, the future of their underlying case abroad. Defending against extradition is one of the most demanding areas of international criminal law: it requires coordinating two or more jurisdictions at once, handling urgent deadlines and knowing precisely which regime applies. This guide explains, in general terms, how that defense is structured before the National Court (Audiencia Nacional) and what tools exist to oppose an improper surrender.

Two regimes: European Arrest Warrant and passive extradition

The first thing that shapes the strategy is identifying under which regime surrender is sought, because the deadlines, grounds for opposition and room for argument all depend on it.

Within the European Union, the European Arrest Warrant (EAW) applies, governed in Spain by Law 23/2014 on the mutual recognition of criminal decisions in the European Union. It is a simplified instrument built on mutual trust between member states: the grounds for refusal are exhaustively listed, the dual criminality check is waived for a list of offense categories, and processing is urgent, with short deadlines to decide on surrender.

Towards non-EU States, classic passive extradition applies, governed by the Passive Extradition Act (Law 4/1985) and by the bilateral treaty or multilateral convention in force with the requesting country. Here the catalogue of grounds for opposition is broader, the review of dual criminality is full, and the procedure combines a judicial phase before the National Court with a subsequent governmental phase. Knowing which of the two frameworks we are operating in is the defense's first technical decision.

The Interpol red notice

Many procedures do not start with an arrest in Spain, but with an Interpol red notice or diffusion (Red Notice): an international alert that a country requests and that is distributed to the police forces of member states. Its nature should be stated precisely, so as neither to overstate nor underestimate it: a red notice is not in itself an arrest warrant and does not automatically compel surrender, but it may lead to the arrest of the located person when crossing a border and seriously restricts their ability to move and to operate internationally.

Its circulation without sufficient prior screening has been criticized for sometimes enabling its use for pressure purposes. For that reason, one of the most relevant actions is the challenge before the Commission for the Control of Interpol's Files (CCF), based in Lyon: a written procedure, before an independent body, that may end with the blocking or deletion of the alert. The practical rule is anticipation: where possible, it is better to clear the situation before international travel rather than having to defend against an arrest that has already occurred.

Grounds for refusing surrender

The core of the defense lies in identifying and substantiating the applicable ground for refusal. As a general matter, and without prejudice to the specifics of each regime and treaty, the grounds most frequently invoked are the following:

• Prior final judgment (ne bis in idem): that the same facts have already been judged definitively, so they cannot be prosecuted again.
• Time-barring: that criminal liability for the facts is time-barred under the applicable law, which requires reconstructing the chronology and the acts that interrupt the limitation period.
• Lack of dual criminality: that the conduct described in the request is not an offense in Spain, an essential prerequisite outside the categories of simplified surrender.
• Political nature of the offense: a traditional ground for refusal in classic extradition, subject to limits and exceptions depending on the treaty.
• Nationality and service in Spain: the status of national as a ground for opposition or, under the EAW, as a basis for requesting that any sentence be served in Spain.
• Risk of breach of fundamental rights: where surrender would expose the person to a real risk of inhuman or degrading treatment or of a breach of fair-trial safeguards in the requesting State.

Not every ground is available in every case: the catalogue is narrower under the EAW and broader in classic extradition. The defense's task is to select the viable grounds and build the evidence for each one, because every ground for refusal has its own evidentiary basis.

Dual criminality and procedural safeguards

Two issues deserve specific treatment because of their weight in practice. The first is dual criminality: the requirement that the conduct for which surrender is sought be an offense both in the requesting State and in Spain. In classic extradition this review is full and usually requires a comparative legal analysis to show that the conduct described does not fit any Spanish criminal offense. Under the EAW, by contrast, this check is waived for a set of predefined offense categories, so the debate shifts to the correct classification of the facts within those categories.

The second is respect for fair-trial safeguards. Surrender cannot be ordered at any cost: where there are serious indications that the requesting State will not respect the right to a fair trial, or that the person will be exposed to prohibited treatment or to detention conditions incompatible with their rights, that circumstance operates as a limit on surrender. Establishing it is not achieved through generic assertions, but through concrete reports and evidence on the situation of the case and of the country, which the defense must gather and submit to the procedure.

Timeframes and the requested person's situation

The time factor conditions the whole defense. The EAW is subject to urgent processing and short deadlines, which means working on all fronts in parallel from the outset: arguing the personal situation, preparing the grounds for opposition and gathering documentation from abroad, which often takes time to arrive. Classic extradition is more protracted, because the governmental phase and, frequently, appeals are added to the judicial procedure.

In both cases, one of the first decisions concerns the personal situation: whether the requested person remains in custody or at liberty under precautionary measures while the matter is resolved. Establishing ties —residence, activity, links in Spain— is essential to support release during the procedure. And there is an underlying strategic decision: whether or not to consent to surrender. Consent speeds up the process and may translate into more favorable conditions; opposing it opens the discussion of the grounds for refusal but prolongs the uncertainty. There is no universal answer: it depends on the strength of the grounds, the personal situation and the requesting State, and it must be assessed with specialist advice before the first appearance.

International coordination before the National Court

An extradition is, by definition, fought in at least two countries at once, and a lack of coordination between the defenses is one of the greatest risks. While surrender is being argued in Spain before the National Court, the underlying case continues to run in the State of origin. That is why, when the case requires it, we activate a network of correspondent criminal-defense firms in the jurisdictions involved, so that the opposition to surrender in Spain and the defense in the requesting country follow a single strategic thread and do not contradict one another.

This coordination allows each jurisdiction's deadlines to be managed without surprises, what is established in one procedure to serve in the other, and the asset dimension —where precautionary or freezing measures are involved— to be addressed in parallel and coherently. The defense against the extradition of international and high net worth clients has its own dedicated page, and the general framework of extradition and EAW proceedings is set out in our specific section.