Impeachment Trial · Evidence Desk
Calilung Authenticates Duterte Threat Video as Defense Tests NBI Probe
The prosecution’s first witness established how the NBI preserved and examined the recording, while the defense challenged the absence of a complainant, the conditional wording and the investigation’s legal foundation.
Event: 8 July 2026 · Published to the FMB News archive: 5 August 2026
The first witness and the recording
National Bureau of Investigation senior agent John Mark Calilung became the first prosecution witness on Article IV of the impeachment case against Vice President Sara Duterte. The article concerns Duterte’s statements during a November 2024 online press briefing in which she said she had instructed a person to kill President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos and then House Speaker Martin Romualdez if she herself were killed. Calilung told the Senate impeachment court that the NBI collected and preserved copies of the recording and examined them as part of its threat investigation. His testimony was offered to establish that the material shown by prosecutors was an authentic copy of the publicly circulated video, not a fabricated clip created for the trial.
What the prosecution tried to establish
Prosecutors used Calilung to lay the technical and investigative foundation for the digital evidence. They argued that the recording had been identified, preserved and examined through the bureau’s procedures and that the statement could be investigated even without a formal complaint from the officials named. The prosecution’s position was that threats against the country’s highest officials involve public security and can trigger government action on their own. This was an evidentiary step, not yet a finding that Duterte committed an impeachable offense.
How the defense challenged him
During cross-examination, defense counsel Carlo Narvasa questioned the chain of custody, the lack of a direct complainant and whether the wording described a completed threat or a conditional response to a feared attack. The defense pressed the distinction because Article IV does not turn only on whether the words were spoken. The senator-judges must eventually decide what those words meant, whether they demonstrated a genuine threat and whether the conduct rose to the constitutional level required for conviction.
What remained unresolved
Calilung could authenticate and describe the investigation, but he could not by himself settle the central legal and factual disputes. Authentication establishes that a recording is what a party claims it to be. It does not automatically prove the intent behind every statement, identify the person Duterte said she contacted or establish that an assassination plan existed. Those questions remained for later witnesses, the defense and the senator-judges.
Why It Matters to Us, Filipinos
The hearing showed why impeachment trials must be built in public, one piece of evidence at a time. Filipinos are entitled to examine both the seriousness of statements made by powerful officials and the reliability of the process used to judge them. A public official’s words can carry security consequences, but accountability also requires evidence that survives careful questioning. The country gains nothing from treating an allegation as a conviction, or from dismissing documented statements without examination.
What happens next
The prosecution called additional NBI officials to reinforce the authentication, explain the bureau’s investigative process and present the conclusions reached by its leadership. The defense retained the right to challenge every document, inference and opinion offered under Article IV.