By Charles Pemu 
ABUJA—A Department of State Services (DSS) operative provided crucial testimony at the Federal High Court in Abuja on Wednesday, asserting that alleged terrorist negotiator Tukur Mamu acquired significant assets and sponsored foreign travel for his family after purportedly receiving proceeds from ransom negotiations following the 2022 Abuja–Kaduna train attack.
Testifying behind a protective screen as the sixth prosecution witness (PW-6), the operative claimed that Mamu’s lifestyle experienced a sudden and conspicuous change, indicating he was “living way above his means” during the negotiation period.
Under examination-in-chief by DSS counsel David Kaswe, and subsequent cross-examination by defence counsel Johnson Usman (SAN), the witness detailed the alleged evidence of financial gain. He confirmed that Mamu was arrested in Egypt while sponsoring a trip for himself and four family members. Additionally, Mamu allegedly purchased two cars during the exact timeframe of the ransom negotiations.
The witness maintained that Mamu was never officially mandated by the Federal Government to engage in discussions with the terrorists and was not a part of the Chief of Defence Staff Committee established for the passenger release. The prosecution’s position is that Mamu “acted on his own for his benefit,” facilitating illegal payments and collecting ransom on the terrorists’ behalf.
The court was also reminded of Tuesday’s testimony, where PW-6 alleged that Mamu was offered ₦50 million as a personal reward by the terrorist leader, “Shugaba.” An audio recording, purportedly extracted from Mamu’s seized Samsung tablet and mobile phones, allegedly captured the leader instructing Mamu to “remove N50m” from a ransom payment. The witness further alleged that cash exhibits recovered from Mamu’s Kaduna residence were in excess of the threshold permitted by law, and that Mamu possessed illegal firearms and advised the terrorists on website creation.
Defence Challenges Investigative Diligence
The defence team, led by Usman, rigorously challenged the integrity and diligence of the DSS investigation. Usman highlighted that the witness admitted to never having a personal encounter with Mamu before the train attack in March 2022, and therefore lacked knowledge of his net worth or previous lifestyle.
The defence further sought to discredit the “sudden wealth” claim, arguing that Mamu already owned two of the three cars—a Toyota Venza and a Mercedes Benz E350—before the incident, and had a prior history of sponsoring family trips for religious pilgrimages like Hajj and Umrah. Usman also noted that despite Mamu’s passport being in DSS custody, the witness admitted he did not open it during the investigation, relying instead on a preliminary report.
While the witness conceded that victims had initially proposed several names as negotiators, he insisted that Mamu was the only one who actively engaged with the terrorists and deliberately sidelined the official government committee.
Justice Mohammed Garba Umar adjourned the proceedings for the continuation of the cross-examination of the witness to January 29, 2026.