507.In no circumstances is probative value ascribed to information obtained anonymously, information that arresting officers claim to receive from detainees, or information obtained by inferences or references of another person, but only that they learnt through personal experience. 508.The suspect’s statement will be admissible only when given before the Prosecution Service in the presence of his defence attorney or a person of trust; if he denies the facts alleged against him, the circumstances arising from his statement are assessed and if it is corroborated by any evidence, or unlikely or contradicted by other reliable evidence. 509.A testimony given by victims or injured parties to the relevant official may be admitted as evidence only where it is considered to have been given by a person whose ability and education equip them with the necessary discretion to judge the event, and check whether the facts set out in the statement were known to the person themselves rather than being inferred or referred by another person; the above factors, taking account of other evidence, such as all the other objective and subjective circumstances which, by applying logic and proper reasoning, indicate whether the testimony is true or false. 510.Statements made by protected witnesses will be admitted as evidence where the information they contain tallies with the other material evidence and the latter tends to confirm it, since it cannot in principle be regarded as prevailing or bound to be accepted, simply because the witnesses were presumably members of the criminal organization about which they are testifying. 511.It follows that the evidence supporting the precautionary measure of preventive custody should be well-founded, proving the possible involvement of the accused in committing the offence in question. 512.In conclusion, there must be no doubt that there are grounds for the prosecution service to continue to investigate the accused and therefore justify extending their detention by means of preventive custody, given the nature of the criminal act under investigation, and that the time available to the relevant federal official is insufficient. 513.It should be emphasized that the forms of evidence described are merely a representative sample of the universe of evidence provided by the relevant official when requesting the precautionary measure. Decision 514.Once the study is complete, the relevant decision is issued and the federal prosecutor is notified, who is required to notify the accused of the measure and provide the information needed to verify that the accused is aware of the court order, and the reasons for applying the measure. Enforcement and monitoring of the measure 515.In general terms, the Federal Prosecution Service is subject to the following obligations for administering the precautionary measure: (a)Monitoring is the responsibility of the federal prosecutor, with the assistance of the police officers under his command; (b)The federal prosecutor is obliged to notify the date of remand, when this occurs, or of release decided for persons in preventive custody and any other decision substantially affecting the investigation in which preventive custody is ordered; (c)It is stipulated that enforcement may not invade the privacy of accused persons, must respect their human rights, and their health and physical integrity must be regularly checked; the method of implementation and observance of the conditions of enforcement must be notified; (d)The judge, or a judicial official empowered by order of the judge, may at any time at his discretion or at the request of a person in preventive custody go to the place of detention to check that the protective measure is being carried out in accordance with the conditions laid down in the authorization and that the fundamental guarantees of the detainee are being honoured. (e)The relevant official is required to report periodically on the implementation of the measure and the progress of the investigation; (f)Preventive custodygenerally takes place at the Federal Centre of Investigation, located at Ignacio Morones Prieto 43, colonia Doctores, borough of Cuauhtemoc, Mexico City, and in exceptional cases the federal prosecutor requests authorization for it to be carried out at another address in view of special circumstances; this is allowed only where that place adequately meets the security and logistical criteria for the proper conduct of the protective measure. Extension of preventive custody 516.Where the federal prosecutor considers it necessary, it makes a new application to the Federal Judge to request the extension of the precautionary measure already authorized. 517.Article 16 of the Constitution, transitional provision 11 of the decree amending and supplementing various provisions of the Constitution of the United Mexican States, published in the Official Gazette of the Federation on 18 June 2008, and in particular article 12 of the Federal Act to Combat Organized Crime, amended by the decree published in the Official Gazette of the Federation on 23 January 2009, indicate that, where the relevant federal official demonstrates that the grounds that gave rise to the protective measure still apply, the current text of the provision referred to above allows it to be extended up to a total of 80 days. 518.To authorize the extension of preventive custody: