Latin American Criminal Justice

The goal of this project is producing knowledge that can be used by researchers and policy-makers about how Latin American criminal justice systems are actually working.

Based on an original methodology for the region that gathers data on a representative set of randomly selected cases directly from court files and prosecutor files, the project gathers data on, among other issues (1) the demographic profiles of victims and defendants in Latin American criminal proceedings; (2) the quality of the police investigation and to what extent it is tested by prosecutors, defense attorneys and judges; (3) how cases are disposed by Latin American criminal justice systems; and (4) the costs of criminal justice.

Jurisdictions studied or that we are planning to study include Argentina, Chile, Colombia and Mexico. The project is pursued with a net of researchers in Latin America, including researchers from the School of Law of CIDE in Mexico, the Universidad Nacional de Tres de Febrero in Argentina, and Universidad Diego Portales in Chile.

Download the report on the state of Mexico (Spanish) 

Download the report on the state of Argentina (Spanish) 

Press Releases

  • Main findings from the report on Mexico

    October 21, 2016 Study Led by UCLA Researcher Highlights Shortcomings of Mexican Criminal Justice Reform Effort

    A new study led by UCLA Professor of Law Máximo Langer has found that recent criminal justice reforms in the state of Mexico have resulted in expeditious processing of criminal cases, but present deficiencies regarding respect of defendant’s rights, the quality of defense, and the quality and control of police investigations.

    On June 18, 2016, Mexico put into effect an adversarial system to investigate, prosecute and adjudicate criminal cases. Reforms included the introduction of public hearings and trials, appointment of a pretrial judge to oversee work by police and prosecutors, plea bargaining and mechanisms for diversion of cases. This national reform was preceded by a number of the state reform efforts. The state of Mexico – the most populous state in the country of Mexico, with 17 million people – instituted reforms in 2009.

    Researchers from UCLA, CIDE University in Mexico and Universidad Tres de Febrero in Argentina examined a representative sample of 1,145 cases adjudicated in the state of Mexico between 2010 and 2014 to determine how the criminal justice system has worked in the state of Mexico and to identify ways in which it may be improved in that state and throughout the country.

    Key findings:

    The criminal justice system of the State of Mexico concentrates on noncomplex criminal cases (e.g., 59.3 percent were robberies, mostly committed by a single person) and cases against young low-income defendants (39 percent of defendants were between 22 and 30 years old) without a prior record (85.1 percent of arrestees).

    Sixty-one percent of the cases are adjudicated through guilty pleas and 12 percent of cases are disposed through diversion mechanisms, which typically involve the dismissal of a case after the defendant has made reparations to the victim or fulfilled certain conditions. Only 3.6 percent of cases go to trial.

    The adversarial system disposes of most cases expeditiously. For instance, 76.9 percent of guilty pleas are entered in less than a month, and only 3.2 percent of pretrial phases last more than six months.

    In an overwhelming majority of cases, arrests are made on the spot and without a warrant (91.7 percent). Warrants are provided in only 8.3 percent of cases. This suggests low investigative capacity by the police and prosecutors.

    According to Mexican law, a doctor must examine a defendant once he or she has been arrested, in order to document any possible evidence of torture or inhumane treatment by police. In 18 percent of cases, the defendant shows signs of physical torture or cruel or degrading treatment by the police. In nearly all cases – 97.4 percent – state courts neither exclude evidence nor order an investigation when there are signs that defendants have been subjected to physical abuse by the police.

    The study found that bail is denied in 71.3 percent of cases.

    Defense attorneys are appointed only when defendants are brought before a judge, but not in the police phase (only 10.3 percent of defendants have an attorney during the police investigation phase). Also, the quality of work by defense attorneys seems to be low, since defense attorneys did not provide any element of proof in favor of their client in the pretrial phase in 76.9 percent of cases and did not present any appeals in 86.2 percent of the cases.

    The prosecutor and the judge do not test police investigations. During the pretrial phase, in 61.5 percent of cases neither the prosecutor nor the judge gathered any elements of proof different from the ones already provided by the complainant or the police. In 64.1 percent of the cases, no elements of proof different from the ones already provided by the complainant or the police were presented at trial.


    This study suggests that while the adversarial system in the state of Mexico provides an expeditious response to cases, it presents weaknesses in the quality of police investigations, the extent to which it respects defendants’ rights against torture and pretrial release, the quality of the work by defense attorneys, and the extent to which prosecutors and judges test the investigation by the police and judges enforce defendant’s rights.

    “How Are Cases Adjudicated in the State of Mexico: A Report on the Operation of the Adversarial Criminal Justice System” is a collaboration led by Máximo Langer, director of the Transnational Program on Criminal Justice at the UCLA School of Law; Gustavo Fondevila of the Centro de Investigación y Docencia Económicas (CIDE), Marcelo Bergman of the Universidad Nacional de Tres de Febrero, Carlos Vilalta and Alberto Mejía of CIDE.

    The study was funded in part by UC-Mexus and CIDE, Centro de Investigación y Docencia Económicas, and the UCLA Transnational Program on Criminal Justice.

    Mexico Evalúa, a think tank in Mexico, published the report and disseminated it through an event in Mexico City and Spanish-language media.

    The report has been cited in more than two dozen Spanish language news media outlets in Mexico.

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