Arraigo — Preventive Detention in Mexican Criminal Proceedings

What is arraigo?

Arraigo is a form of preventive detention in Mexican criminal proceedings, originally anchored in Article 16 of the 1917 Constitution (CPEUM). It allows a person to be held without a formal charge for up to 40 days — extendable to up to 80 days in cases of “organized crime” (delincuencia organizada). The measure is ordered on the application of the public prosecutor's office (Fiscalía) by a federal detention judge.

SCJN ruling Acción de Inconstitucionalidad 29/2012

By judgment of March 16, 2017, the Suprema Corte de Justicia de la Nación (SCJN) held in Acción de Inconstitucionalidad 29/2012 that the application of arraigo to state-level offenses is unconstitutional. The measure nonetheless remains permissible for federal organized-crime offenses (Article 16(8) CPEUM). The reform of June 18, 2008 (Sistema Penal Acusatorio) gave arraigo a constitutional footing; its complete abolition has been debated in Congress on several occasions.

Criticism by the UN Committee against Torture (CAT)

In several Concluding Observations on Mexico — most recently in 2019 — the UN Committee against Torture (CAT) has called for the abolition of arraigo. The measure creates “conditions that facilitate torture and ill-treatment” (CAT/C/MEX/CO/7). The UN Special Rapporteur Juan E. Méndez likewise documented specific torture allegations in the arraigo context in his Mexico report of 2014/2015 (A/HRC/28/68/Add.3).

Significance for extradition proceedings

In extradition to Mexico, the arraigo practice is a central argument under Article 3 ECHR and Section 73 IRG: after surrender, the requested person may be placed in arraigo without the German authorities having demanded specific guarantees. Diplomatic assurances to avoid arraigo must be secured as part of the defense — by analogy with the practice in US extraditions involving a risk of solitary confinement.

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