Amid concerns that videos presented may be generated through Artificial Intelligence (AI), senator-judges asked National Bureau of Investigation (NBI) Senior Agent John Mark Calilung if what was presented was authentic or not.

During the third day of the impeachment trial on Wednesday, July 8, Senator Raffy Tulfo asked Calilung, after the cross-examination of the defense counsel of Vice President Sara Duterte, if he is experienced enough to analyze whether a video is AI-generated or authentic.

According to Calilung, he's experienced enough to determine this since AI-generated videos are usually short, yet the video in question is two hours long.

A day before, the prosecution presented a portion of Duterte's more than two-hour online press conference on Nov. 23, 2024, where she was heard saying she had supposedly instructed someone to kill President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos, and former House Speaker Martin Romualdez if she herself were killed first.

Also played was Duterte's Oct. 18, 2024, statement, in which she spoke about her already “toxic” relationship with the President, in which she also mentioned imagining the "beheading" of President Marcos and remarked about exhuming the remains of the late former President Ferdinand Marcos Sr. and throwing them into the West Philippine Sea.

Tulfo also asked whether the NBI had examined public reactions to the Vice President’s video. Calilung testified that some comments agreed with the Vice President’s statement regarding the killing of the President, while others allegedly called for a people power movement.

On the other hand, Senator-judge Robin Padilla asked about the chain of custody of the video evidence involving Duterte.

When Padilla asked whether investigators were able to obtain the original video file or an affidavit from the person who made the original recording, the witness admitted that the NBI did not obtain the original file, explaining that the recording they preserved was taken from a video publicly available on the internet using OBS screen recording software.

Padilla emphasized the importance of securing the original file, stating that this is necessary to determine whether the evidence is indeed original and authentic.

Padilla also requested that the impeachment court require the submission of the witness’s complete credentials, certifications, and qualifications to establish his expertise as an NBI Cybercrime Division investigator.

Senator-judge Vicente "Tito" Sotto III only asked if Calilung is aware of a notice regarding videos generated through AI that's posted on social media, which he said he knows of.

Lastly, Senator-judge Panfilo Lacson asked Calilung if he agreed that AI videos are hard to tell apart from authentic ones, to which he agreed.

Lacson also questioned him about the digital forensic tools that he used while he was in the Digital Forensic Laboratory Division, wherein he mentioned a software called Amped Authenticate. Lacson asked if he used this tool.

According to Calilung, he didn't use this tool since the video was too long, and resorted to manual comparison of the video he obtained and the original source. Lacson said that this is not reliable.

"Mas importante makuha mo yung original copy para masundan mo, sa analysis, gagamitan mo ng tools para malaman mo na talagang authentic yung video (It’s more important to get the original copy so you can follow it, and in the analysis you’ll use tools to verify that the video is truly authentic)," he said.

"I'm not here to question the authenticity; I just want to be assured dahil sabi ko nga kanina sa AI napakahirap talaga (because what I said earlier), almost impossible to distinguish it from the original source," he added.