According to the current social juncture experienced by the Colombian justice administration in terms of the propagation of injustice and judicial errors caused by the positive evidential valuation of false witness, this research and its critic which is related to the superficial estimate done to the testimonial evidence by some of our judges, and the acceptance withalmost non-control of the Attorney General´s Office, is sprang up.In this sense, an exhaustive but concise research to respect all the relevant factors when assessing the witness and its testimony as an evidence, that sets the diverse formal and considerable requirements which the witness and its statement should enjoy, so they can be taken into account when making a decision in criminal matters.Based on the statements above, this monograph is made up by a theoretical part and a theoretical-practical part, in which the paradigmatic case of the Colonel ® Luís Alfonso Plazas Vega was taken as the principal example, since it is a process which is currently on appeal in the high court, and so far it does not have a final decision by the worshipful Supreme Court. Therefore, it is possible to make our own and constructive critic regarding theassessment of the testimonial, in the understood that is not an unmistakable decision.Finally, the aim of this work is to explain in a simple manner and easy understanding thework performed by the judges of the Republic and the Attorney General´s Office, that even it is not a decision making process, it should also make a minimum valuation or at least check on time and give credibility to the witness who are favorable to their case theory. Such as, the Justice administration should carry out a evidential valuation, specially aimed to the evidentiary standard that should be given to testimony, considering external and internalfactors that can affect such testimony, and therefore it should be influenced itself; foregoing matters, in order to avoid justice errors that have been taking place throughout our history which have led to innumerable injustices, creating great controversy and uneasiness in the civil society.
