Prosec opposes expert verification of open-source evidence in ICC trial

MANILA, Philippines — The Office of the Prosecutor at the International Criminal Court (ICC) has opposed the request of former President Rodrigo Duterte’s defense team to require expert verification in submitting publicly available or open source materials submitted as evidence in trial.

Duterte’s defense team previously proposed an amendment to the international court’s E-Court Protocol to include an expert report to accompany all forms of open source and user-generated evidence to be submitted at the trial, citing the need to avoid “being overwhelmed by material of dubious relevance, authenticity and reliability.”

“It is unreasonable, unnecessary and against the interests of judicial efficiency, to require an expert report to accompany all forms of open source and user-generated evidence,” ad interim Prosecutor Mame Mandiaye Niang asserted in a letter dated September 9.

READ: Prosecution to ICC: Admit witness’ testimony on Duterte ‘DDS’ model

Niang noted that due to the broad definition of open source information, the need to call for expert verification on a piece of user-generated evidence should instead be made on a case-by-case basis.

These cases that require experts, Niang enumerated, may include disputes on whether the open source evidence is “edited in any way” or if “[artificial intelligence] tools were used to filter the evidence.”

He added that such verification need not apply to publicly available information from reputable sources.

“The Prosecution submits that expert evidence is not necessary to accompany certain other forms of open source evidence from reputable sources. For example, reports from organisations such as the United Nations, government websites, NGOs such as Human Rights Watch, and reputable news publications should not require expert evidence in order to be submitted,” Niang said.

Niang pointed out that the chambers of the ICC have previously allowed open source evidence from reputable sources without an expert report.

Further, Niang asserted that the defence will have the opportunity to challenge the admissibility of open source evidence upon introduction during the trial.

“The Prosecution agrees with the Defence that the Court must be vigilant in its assessment

of open source evidence in the age of artificial intelligence and disinformation… However, the Prosecution submits that the Court must be proportionate in its response to these concerns and not create significant burdens that unnecessarily hamper judicial efficiency and ultimately, risk delaying the start of the trial,” the prosecutor pressed.

READ: Duterte ICC case: Nearly 7,000 evidence items disclosed ahead of trial

As of September 3, the prosecution has intended to disclose over 25,000 pieces of evidence, and it expressed intention to disclose 200 gigabytes of material.

Duterte is awaiting trial on November 30, 2026 at the ICC for two counts of murder as crimes against humanity, and one count of murder and attempted murder as a crime against humanity for his supposed role in the drug war during his presidency and when he was mayor in Davao City. /jpv