From Halopedia, the Halo wiki
During the Battle of Mombasa, he broadcast propaganda to trapped civilians in the city. He and Mike Branley had a confrontation when the latter found him broadcasting from a room near the NMPD HQ's communications hub. Stephen had said in a broadcast that NMPD officers Marshall Glick, Roberto Bustamante, and Jim Odingo were heroes who had been killed while battling Covenant invaders by snipers, who were in turn killed by civilians from New Mombasa. In reality, Glick had lost his mind from the stress of the invasion, and killed Bustamante, Odingo, and any other officers who he had any kind of negative feelings towards, before being killed himself by the NMPD SWAT team.
Mike accused Stephen of being a liar, and Stephen argued that he was giving hope to the "doomed" citizens of New Mombasa in their final hours. In an attempt to prove his point, Stephen put Mike on the air, daring him to "tell the truth." Mike quickly found himself telling the same kinds of lies that Stephen had, even claiming that civilian efforts against the Covenant were "going well".
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