Broadly speaking, evidence provisions are not very detailed by electoral laws. Many times, no clear rules can be found at all. In some cases, the rules contained in traditional procedural statutes (Civil Code, Administrative Code) are used in electoral litigation, especially to admit and evaluate evidence brought by contesting parties (Bolivia, Guatemala, and Paraguay). Those countries that allow filing electoral appeals at ordinary courts usually allow the use of traditional procedural statutes to manage evidentiary issues. Some conclusions may nevertheless be offered as follows:

a.  Evidentiary Mechanisms

In many countries, it is compulsory to include all documentary evidence within the appeal (Costa Rica, Chile – in those cases in which the voters’ register is challenged–, Ecuador, Mexico and Peru). While some countries authorize both the plaintiff and the defendant to offer evidence to prove their claims (Argentina, Bolivia, Chile, El Salvador, Honduras, and Panama), only a couple of countries establish limits such as considering just electoral documents as valid evidence. In Colombia any kind of evidence can be used to support any appeal filed at the Fifth Section of the Chamber for Administrative Litigation of the State Council. Mexico authorizes the use of public and private documents, technical evidence, judicial files, the so-called human and legal assumptions, confessions, testimonies and experts’ declarations to support electoral appeals.

Most of the cases allow electoral authorities to gather all evidence that can help them in reaching a more satisfying decision (Argentina, Colombia, Chile, El Salvador, Guatemala, Mexico, Panama, Paraguay, Peru, and Uruguay in some cases).

Electoral appeals must be resolved within specific deadlines and the representative agencies of a nation must be renewed in time. Therefore, electoral authorities have established rules according to which they will only admit evidence which can be used to support the contenders’ claims and which has been attached to the appeals within the corresponding time limit. Evidence such as  provided by witnesses can hardly provide courts with relevant evidence for resolving electoral issues. The reason is clear: contenders can offer as many witnesses as they can gather, whose testimonies then could result in many contradictions.

Bearing all this in mind, it is important to highlight that Latin American systems for the resolution of electoral disputes are similar among themselves. While those countries in which admissible evidence is restricted to few cases allow judges to expand the number of things that can be used as evidence (Colombia and Mexico), those other countries that have wider rules for the admission of evidence allow judges to restrain the number of things that can be used as evidence. From both points of view, evidence is a tool that must be used to reach a more satisfying decision before meeting the established deadline.

b.  Evaluating Evidence

From a theoretical point of view, there is a very influential procedural trend according to which different systems to evaluate evidence can be listed as follows: i) System of legal evidence: legislative texts establish how effective evidence can be; ii) System of free evaluation: courts are free to evaluate all the evidence attached to the appeal, in order to reach a satisfactory resolution in a free way. In such a system, judges are free to evaluate evidence from their personal, rational, or moral beliefs. No constraints are imposed upon judges in charge of resolving appeals; iii) System of rational evaluation: In such a system courts are empowered to determine how effective a proof can be considered. To do so, judges have to use logic and base their decisions on their experience. The system of rational evaluation is somewhere in between the other two; and iv) Mixed System: Elements of the previous systems are combined.

Very few electoral laws define the way in which evidence has to be evaluated to resolve electoral disputes. Three countries establish a system of free evidence (Colombia, where the National Electoral Council and its delegates are free to evaluate factual evidence; Chile, where the Tribunal for the Validation of Elections will work as a jury to evaluate factual evidence; and Peru, where the National Jury for Elections is empowered to resolve appeals evaluating evidence on their own). Two countries demand rationality from their electoral authorities (Costa Rica and Panama), while a single country establishes the system of legal evidence (El Salvador sets down not only that no more than three witnesses can be called to testify, but also that testimonies will never be enough to nullify an electoral order). Mexico follows a mixed system because not only public documents are recognized there as the most valuable evidence. Electoral authorities are also compelled to be rational.  

In conclusion, “Election disputes are inherent to elections. Challenging an election, its conduct or its results, should however not be perceived as a reflection of weakness in the system, but as proof of the strength, vitality, and openness of the political system.”[i]