How important is the chain of custody to guarantee the validity and integrity of evidence in a criminal proceeding?
The importance of the chain of custody is based on the fact that the materials and objects that are seized in any criminal act do not suffer or are corrupted by alterations, substitutions, contamination or destruction. That is to say, that the elements of evidence that are incorporated and exhibited in an oral trial maintain physical identity with the material that has been found, collected and seized in the place where it is stated that the crime or the fact of criminal relevance occurred, and that they are in identical phenomenological conditions to those they had there.
Therefore, it is of vital importance that the evidence be kept in a safe place, protected from any factor or person that could alter it, with or without intention, not only to ensure its integrity, conservation and unalterability to be sent to the competent judicial authority, but to guarantee phenomenological identity for when they are presented at the oral trial stage.
¿What requirements must a piece of evidence meet for it to be admitted as such in an oral trial?
First of all, we must outline what the appropriate procedure is in this matter. Specifically, the appropriate collection of evidence must be met; proper preservation of evidence; and the controlled delivery of evidence.
The requirements are diverse. The most important and determining factors are to establish a rigorous and detailed record that identifies the evidence and its location, for which extremely suitable means must be used.
What challenges does chain of custody pose in the context of digital or electronic evidence, such as emails, text messages, or audio or video recordings?
Let us start from the basis that if the chain of custody is not respected in the simplest criminal acts in terms of investigation (such as a theft), it is even less respected in the context of technological and digital evidence, whether emails, messages. text, audio recordings, videos, txt files, etc.
Digital or electronic proof can be modified very easily. For this reason, there are accepted protocols such as the ISO 27,037 standard or the HASH chain of custody manual, which are the ideal means to secure digital evidence.
This issue is conspicuous by its absence in our procedural codes both at the federal level and at the level of the different provinces.
What measures can be taken to prevent alteration, loss or destruction of evidence during collection, transport, storage and analysis?
The measures that must be taken are of various kinds, such as the appropriate extraction of evidence; its preservation, since the environment in which it is placed must ensure that its properties are not altered; the individualization of the evidence in a way that guarantees that the evidence is properly recorded; adequate transportation where the identity of the evidence is safeguarded so that it is not damaged or altered; controlled delivery stating who found it, who collected it, where and under what circumstances.
What consequences can non-compliance or breaking the chain of custody have for the case and for the parties involved?
In general terms, when it comes to the seizure of evidence at the crime scene, we are going to be faced with definitive and irreproducible acts: that is, when said acts are carried out, they cannot be reconstructed again.
Clearly, the consequence of the non-compliance of the parties involved or the breaking of the chain of custody will be the declaration of the nullity of that act due to the impact of constitutional guarantees such as the right of defense and due legal process.
In that sense, if during the development of the criminal investigation and later the oral debate, the accused and his defense understand that the seized material is different from what was actually found at the place of discovery, there is no way to reproduce that act. initial of the kidnapping to verify that point in controversy and therefore, it becomes necessary to declare the annulment of that kidnapping and everything acted as a consequence. The solution for the judge will be to dismiss or acquit the accused of the crime.
by CEDOC
