The 61st session of the ongoing trial involving First Vice President Dr. Riek Machar resumed on Wednesday at Freedom Hall, with proceedings focusing on the continued cross-examination of the prosecution’s final witness, digital forensic analyst Peter Rafadi Calvin.
The defence team pressed the witness on the scope and reliability of his forensic report, particularly the interpretation of digital materials extracted from devices linked to the accused.
During questioning, Calvin told the court he could not identify the sender or recipient of certain video files presented as evidence.
He explained that his role was limited to extracting and reviewing content, without determining who transmitted the materials.
The court also heard that some of the digital files examined dated back to February 2025, before the Nasir incident, while others were recorded after the arrest of one of the accused, Petroleum Minister Puot Kang Chol.
Defence lawyers challenged the relevance of the materials, describing them as general in nature.
In response, Calvin said he relied on keyword searches, including terms such as “gun,” alongside his own analysis to identify potentially relevant content.
Under further questioning, the witness acknowledged he could not confirm the timeline of certain images and videos, nor verify whether the accused was in custody when some files were received.
The court was also told that no independent confirmation from telecommunications authorities was obtained to link specific phone numbers to the accused.
Calvin admitted that some conclusions in his report were based on his interpretation rather than direct evidence.
On financial evidence, the witness referred to an alleged transfer of $1,500 but said there was no documentation directly proving the transaction originated from the first accused.
He added that he could not determine the location of the accused at the time certain messages were received.
Questions were also raised about the process through which the forensic expert was engaged.
Calvin testified that his firm was contracted via the South Sudan Embassy in Pretoria in June 2025.
He said he was not aware of any competitive procurement process or other bidders.
Additionally, he confirmed there was no direct government-to-government request between South Sudan and South Africa regarding the forensic services.
The session concluded with the presiding judge adjourning proceedings to Wednesday, 25 March 2026, when cross-examination of the witness is expected to continue.
The case centers on Dr. Riek Machar and seven co-accused, who are facing charges of murder, terrorism and treason over the Nasir attack.
Prosecutors allege the incident killed 257 soldiers from the South Sudan People’s Defence Forces and resulted in the destruction or capture of military equipment valued at around $58 million.
Machar has been under house arrest since March 26, 2025, while the other accused remain in detention at National Security Service facilities in Juba.
