The Senate impeachment court on Wednesday revisited Vice President Sara Duterte's controversial  press briefing, but this time the battle shifted from what she said to how the National Bureau of Investigation (NBI) investigated it.

Cross-examining NBI Senior Agent John Mark Calilung, defense counsel Carlo Joaquin Narvasa sought to cast doubt on the factual underpinnings of the bureau's investigation, which accuses Duterte of an assassination plot, grave threats and inciting to sedition over statements she made during the 23 November 2024 livestream.

Rather than challenge the authenticity of the video, Narvasa sought to show that investigators could not fully assess Duterte's statements without understanding the circumstances that prompted them.

Asked whether he had personal knowledge of the House proceedings involving then Office of the Vice President chief of staff Zuleika Lopez, Calilung conceded: "I don't have personal knowledge, sir, because I'm not present during that time."

Earlier, Narvasa also established that the NBI agent had no firsthand knowledge of the alleged assassin referred to in Duterte's remarks.

"You also do not have personal knowledge of the alleged assassin that was allegedly hired by the Vice President," the defense lawyer said.

"No, sir," Calilung replied.

Lopez at center of defense strategy

At Narvasa's request, prosecutors unsealed the USB drive containing the press briefing. Instead of replaying Duterte's controversial statements, however, the defense showed portions of the livestream featuring Lopez, whose detention immediately preceded the press conference.

"Hindi naman po ako criminal. I am not a criminal," Lopez said in the video.

"I would not have pushed that there by myself if I didn't feel that I was being threatened. My life is being threatened," the former Davao administrator added.

Lopez had been cited in contempt by the House Committee on Good Government and Public Accountability during its inquiry into the Office of the Vice President's alleged misuse of confidential funds after refusing to answer lawmakers' questions. 

She was detained at the House of Representatives, and on 22 November 2024, the committee ordered her transfer to the Correctional Institution for Women in Mandaluyong City.

The transfer prompted Duterte to rush to the House complex, where she stayed with Lopez inside the detention area.

According to the defense, Lopez was supposed to address reporters through a virtual press conference from her detention room. But after suffering what Duterte described as an anxiety attack, the Vice President took over the livestream.

It was during that broadcast that Duterte declared 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 own life succeed—remarks that later became the basis of the NBI investigation, criminal complaints before the DOJ and the fourth article of impeachment.

Narvasa then asked Calilung whether those events had been considered in the NBI's investigation. Although the witness said he investigated the incident, he acknowledged that he was not present during the House proceedings. He also confirmed that Lopez's statements formed part of the materials considered in his revised affidavit.