The House prosecution panel on Tuesday presented National Bureau of Investigation (NBI) Senior Agent John Mark Calilung as its first witness in the impeachment trial of Vice President Sara Duterte before the Senate sitting as an impeachment court.

During the proceedings, House prosecution counsel Atty. Amando Virgil Ligutan formally introduced Calilung, describing him as a trained and experienced investigator in the field of digital evidence.

Calilung testified in connection with the fourth article of impeachment filed by the House of Representatives, which accuses Duterte of issuing alleged threats against President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos, and former House Speaker Martin Romualdez.

Before the witness took the stand, the Vice President's defense team, through defense counsel Atty. Carlo Narvasa moved to exclude Calilung from the list of prosecution witnesses.

However, Senate impeachment court Presiding Officer Francis "Chiz" Escudero denied the motion, allowing the NBI official to testify.

During his testimony, Calilung detailed the digital evidence gathered by the NBI as part of its investigation into Duterte's alleged threats against several government officials.

He told the impeachment court that one of the key pieces of evidence was a video of the Vice President's online press conference in November 2024, which was posted on the Facebook page of former presidential spokesperson Harry Roque.

"One of the pieces we gathered is the video of the November 2024 online press conference held by the Office of the Vice President and posted on the Facebook page of Harry Roque," Calilung testified.

The witness also disclosed that the NBI formally requested Meta to preserve a copy of the video containing Duterte's statements regarding President Marcos, the First Lady, and Romualdez.

The defense objected to the introduction and identification of the video, arguing that it was not a certified true copy. However, Escudero overruled the objection and allowed the evidence to be presented.

The presiding officer likewise rejected the defense's objection questioning Calilung's competence to testify on Meta's preservation process in relation to the requested video.

Calilung testified that the NBI took additional steps to preserve and authenticate the digital evidence. He said investigators created a screen recording of the video from beginning to end, compared the recorded copy with the original November 23, 2024 video, and verified that both versions contained identical content.

The impeachment trial continues with the prosecution expected to present additional witnesses and documentary evidence in support of the articles of impeachment against the Vice President.