In registration and follow-up, the chain of custody begins from the complaint and at the time of the investigation, and those who intervene in an additional way are the prosecutor, the police and the experts (in fact, this is how the investigative trilogy is composed) and must be coordinated in a very clear way in order to be able to work as a team and carry out the investigation for the other phases of the process. Once the request has been received and the interdisciplinary group that will be active in the investigation of the crime has been formed, it will immediately go to the scene of the facts and / or conclusion to avoid the loss of clues or evidence. In the event of modification or imitation of one of those phases or phases, we would be faced with the absence of legality of the evidence to be used in criminal proceedings, which could lead to erroneous procedural activity or de facto nullity, since the elements raised and analysed have no probative value and would violate the principle of legality of procedural acts which must exist throughout the criminal proceedings. OBJECTIVE: To be based on theoretical and legal assumptions based on the chain of custody of evidence in the Cuban legal system in order to achieve appropriate criminal proceedings. It is a system for recording indications, evidence, objects, instruments or proceeds of the criminal act, which can be used as evidence and finally as evidence in criminal proceedings under article 227 of the National Code of Criminal Procedure and article 25, section XX, of the General Law on the Public Security System. The chain of custody must be a very important issue to be addressed in the oral criminal justice system, and the substance of the evidence and the physical evidence must be confirmed, no doubt expert evidence and scientific evidence have become important in the follow-up. In doing so, the guidelines must be followed by all officials for the proper preservation, treatment and protection of the place of facts or findings, indications, traces or traces of the offence as well as documents, objects or proceeds of crime. However, it has been possible to assess that there are special regulations or laws that collect the chain of custody of fingerprints, evidence or samples of crimes and establish the basic guidelines so that they reach the oral hearing and become evidence. This is what is happening in Peru[17], where a chain of custody regime is established, derived from its rules of procedure, which leaves it to the Public Prosecutor`s Office to dictate this regulation, where Article 7 of this regulation conceives the chain of custody as “the procedure aimed at ensuring the individualization, security and preservation of material elements and evidence, be collected in accordance with their nature or included in an investigation into a criminal offence intended to ensure its authenticity for the purposes of the proceedings`. It also regulates the procedure, format, supervision, managers with their obligations, as well as other aspects of crucial importance. The service phase includes each of the deliveries and receipts that occur during the handling of evidence, that is, it is a daily occurrence for evidence to pass into the hands of several persons and different offices, persons who, exceptionally, may be called as witnesses in criminal proceedings, so this identification must be very clearly indicated on labels or in protocols, which are kept for that purpose. The chain of custody is the procedural safeguard that honestly confirms that the evidence in the trial is what was collected or practiced, and that its integrity has not been replaced or altered throughout the criminal proceedings[10].

1.- Discovery and preservation of the crime scene or crime scene: the place of the fact must be interpreted from a broad angle, since the determination of the clues does not necessarily correspond to the main place where the event investigated took place or where most of the clues are located, but even these can be scattered in several places, or even on the same body of the victim or suspect, all of whom are subject to the same custody rules. The actions to be performed on the site of the events are final, so it is strictly protected, so that they are not modified, since they can not be obtained at another time. The most important aspects that lead us to create theoretical foundations of the chain of evidence in Cuba are: [24] Criminal Procedure Law (updated). Entered into force on 13 August 1977. General Ignacio Agramonte y Loynaz”, May 2012. Article 135 Cf. Rivero García, Danilo: op. cit.

cit., p. 91. Commentary to Article 135 by provisions such as Instruction No. 40 of 1974 on the Care, Preservation and Control of Beliefs in the Court, Opinion No. 57. Convention No. 125 of 20 March 1979 on the Destination of Occupied Drugs provides that the authority responsible for admission to the preparatory phase must collect convictions and keep them so that they can be identified at any time; for example, at the hearing (Article 309). If the offence is a drug-related offence, the court hearing the case may, for security reasons, order the destruction of the case at the request of the Prosecutor, provided that a sample of the proceeds is retained for the above-mentioned purposes. Opinion No.

420. Convention No. 278 of 11 December 2002 on the Destination of Elements Used in Investigations. However, there will always be common aspects in the definitions, so most tend to refer to the chain of custody taking into account the following aspects: 3.- Fixing the footprint or evidence: this phase makes it possible to accurately determine the location and condition of the indices of interest for the investigation. and that they were found on the site of the event, which facilitates the development of versions and a possible reconstruction of the facts, if at any time of the process the need arises to understand the dynamics of the historical event, which can be verified with the exact descriptions that the respective documents must contain. The research is based on the following methods: historical-logic, which has made it possible to know the historical evolution, development and definitions that exist on the criminal process, evidence, source of evidence, chain of custody, taking into account its basic elements; the theoretical and legal doctrine, which made it possible to examine the existing doctrine on criminal procedure, evidence, the source of evidence, fingerprints, samples or evidence, the chain of custody, in order to assess the lack of regulation of the subject in the Cuban legal system; the exegetical and analytical method which, as a typical method of law, allowed a careful analysis of Cuban regulations and revealed the absence of regulation on the chain of custody of evidence in Cuban criminal proceedings. This leads to insufficient doctrinal development in Cuba with regard to the chain of custody of evidence, which implies a legislative vacuum in the Cuban legal system, resulting in due process guarantees. The chain of evidence is the controlled procedure applied to physical evidence relating to the offence, from its location to its assessment by officials in the administration of justice, the purpose of which is not to interfere with the management of such evidence and thus avoid alteration, replacement, contamination or destruction[6]. 2.- Preliminary investigation and search for evidence: once the crime scene has been located and properly guarded, it is important to appoint an investigator, who is the administrator of the treatment of the site, that is, a person with many years of experience, who assumes a leadership role with other colleagues and who is responsible for coordinating with the trainer of the case of technical procedures, those who are looking for physical evidence. [5] HALANOCA HUAMÁN, Julián César. (2009): “Der Tatort und die Chain of Custody im neuen Strafprozess”.

Reproduced in Agenda Magna on February 10, 2009. Accessed February 18, 2012. During the examinations, it is possible to leave the occupied property as a deposit to their owners or owners – with appropriate precautions. in the case of property the custody of which is governed by special provisions; namely, money, jewelry, works of art or weapons, these rules must be respected. Inhabited property that is not related to the crime under investigation is left at the free disposal of the owner or rightful owner. And Agreement No. 29 of 9 February 1988 (as specified by Agreement No. 19 of 14 February 1989). The documents of condemnation, if they refer to the fact that in the professional activity the goods are described in detail and detail, they correspond faithfully to those treated in the context of the deposit procedure. In the event of cremation or destruction, the protocol must contain the reason, witnesses and other information to the authority providing for it.[26] And in the case of the Documentary File of the steps: I appreciate it as a transversal line that crosses all the phases or stages of the chain of custody of the fingerprint or evidence, since there must be a reference file of everything that is done, which is analyzed independently or confronted with the statements of the people who intervened in the investigation. There must be no doubt about its treatment and manipulation, that is, there must be clear evidence that this is an expert study of a strictly scientific nature.