A dispute over the authenticity of electronic evidence took center stage Tuesday in the impeachment trial of Vice President Sara Duterte, as the defense questioned whether Meta records presented by House prosecutors faithfully reflected the original digital documents they sought to introduce before the Senate impeachment court.

House private prosecutor Amando Virgil Ligutan presented an National Bureau of Investigation (NBI) digital forensics agent John Mark Calilung to authenticate electronic evidence related to Duterte's 23 November 2024 livestream, in which she made statements prosecutors say support allegations of culpable violation of the Constitution and betrayal of public trust.

Before the witness could proceed with his testimony, Narvasa objected to the identification of a printed screenshot of Meta's acknowledgment of the NBI's preservation request.

"We note that the exhibit is not an original or certified true copy, and we object to the introduction of this and the identification of this," Narvasa told the Senate impeachment court.

Narvasa's objection claimed a "Certified True Copy" stamp appearing on the lower portion of the document, arguing that the notation could not have been part of an email sent by Meta.

"This Certified True Copy would not have appeared in any correspondence with noreply@records.facebook.com. So it is not a printout, it's not an original. It would not reflect what accurately was printed out or appeared on the screen," he argued.

While Philippine law recognizes printouts of electronic documents as the equivalent of originals, they must accurately reflect the underlying electronic data. 

The defense argued that the additional certification markings cast doubt on whether the exhibit remained a faithful reproduction of the original Meta correspondence.

Ligutan countered that the defense was raising its objection prematurely. Citing the Rules on Electronic Evidence, he argued that a printout of an electronic document is treated as an original, provided it accurately reflects the electronic data, and that questions regarding admissibility should be resolved only when the prosecution formally offers its evidence.

"Presentation of evidence and objection to the admissibility of documentary evidence happens when the documents are formally offered in evidence," Ligutan said.

He explained that the "Certified True Copy" notation was added only after the document had been submitted to the House of Representatives Committee on Justice during its impeachment inquiry and maintained that such certification was not even required under the rules governing electronic evidence.

The exchange prompted questions from Presiding Officer Francis Escudero, who asked prosecutors to explain why a document claimed to be an electronic printout later carried an NBI certification.

Ligutan replied that the certification was placed on the copy submitted to the House committee and did not alter the nature of the underlying electronic document.

Escudero ultimately overruled the defense's objection.

"He may raise his objection at the proper time when formal offer is made of the document or evidence," he ruled, emphasizing that prosecutors were still identifying the exhibit through the witness rather than formally offering it in evidence.

Establishing authenticity

Calilung likewise testified that he personally initiated a preservation request with Meta after investigators examined Duterte's livestream.

He said he captured screenshots of both the preservation request and Meta's acknowledgment using his laptop, saved electronic copies, printed them and submitted the printouts to the House Committee on Justice.

Asked how he knew the printed documents accurately reflected the original electronic records, the witness testified that he compared each printout with the original screenshots and found the contents "identical."

He also testified that Meta acknowledged the preservation request and assigned it a unique case number before he proceeded to preserve the livestream using Open Broadcaster Software (OBS), recording the video from beginning to end together with its URL.

Narvasa again objected when Ligutan asked the witness what Meta's acknowledgment meant, arguing that an NBI examiner was not qualified to interpret the internal procedures of a private technology company.

"He is not from Meta. He doesn't know Meta procedures. The mere fact that he's an NBI agent doesn't make him competent," Narvasa argued.

Ligutan defended the witness's qualifications, citing his experience in digital forensics, specialized training and multiple court appearances involving electronic evidence.

Escudero once again overruled the defense's objection.

A November 2024 live broadcast shows that Duterte publicly declared that she had instructed someone to kill President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos and then-House Speaker Martin Romualdez should an alleged plot against her succeed. 

In an affidavit later submitted to the House Committee on Justice, investigators said their forensic examination found the livestream to be authentic and showed no indication that it had been edited, spliced or generated using artificial intelligence. 

The bureau also said it found what it described as a "reasonable certainty of conviction" for inciting to sedition and three counts of grave threats based on Duterte's statements.

That affidavit formed part of the records considered by the House committee before lawmakers voted to impeach Duterte in February 2025.