Function of chain of custody

The chain of custody is basically the duly recorded authorized stages of transfer of custody of seized dangerous drugs, from their seizure or confiscation to receipt in the forensic laboratory for examination to safekeeping to presentation in court for destruction.[1] The function of the chain of custody requirement is to ensure that the integrity and evidentiary value of the seized items are preserved, so much so that unnecessary doubts as to the identity of the evidence are removed.[2] Thus, the chain of custody requirement has a two-fold purpose: (1) the preservation of the integrity and evidentiary value of the seized items, and (2) the removal of unnecessary doubts as to the identity of the evidence.

The law recognizes that, while the presentation of a perfect unbroken chain is ideal, the realities and variables of actual police operation usually makes an unbroken chain impossible.[3] With this implied judicial recognition of the difficulty of complete compliance with the chain of custody requirement,[4] substantial compliance is sufficient as long as the integrity and evidentiary value of the seized items are properly preserved by the apprehending police officers.[5][1] Section 1(b) of Dangerous Drugs Board Regulation No. 1, Series of 2002 (which implements Republic Act No. 9165) specifically defines chain of custody as follows:

b. “Chain of Custody” means the duly recorded authorized movements and custody of seized drugs or controlled chemicals or plant sources of dangerous drugs or laboratory equipment of each stage, from the time of seizure/confiscation to receipt in the forensic laboratory to safekeeping to presentation in court for destruction. Such record of movements and custody of seized item shall include the identity and signature of the person who held temporary custody of the seized item, the date and time when such transfer of custody were made in the course of safekeeping and used in court as evidence, and the final disposition.

[2] People v. Langcua, G.R. No. 190343, February 6, 2013, 690 SCRA 123, 139.

[3] See People v. Aguilar, G.R. No. 191396, April 17, 2013, 696 SCRA 838. There, the Court said: “While a testimony about a perfect and unbroken chain is ideal, such is not always the standard as it is almost always impossible to obtain an unbroken chain.”

[4] See People v. Rusiana, G.R. No. 186139, October 5, 2009, 603 SCRA 57, 65. There, this Court stated: “[A]lthough ideally the prosecution should offer a perfect chain of custody in the handling of evidence, ‘substantial compliance with the legal requirements on the handling of the seized item’ is sufficient. Behind this is an acknowledgment that the chain of custody rule is difficult to comply with.”

[5] See People v. Langcua, supra note [3] at 139, where the Court says: “As long as the integrity and evidentiary value of the seized items are properly preserved by the apprehending police officers, substantial compliance with the procedure to establish a chain of custody is sanctioned.”