Associated with Starfleet Intelligence, Pressman was commander of the U.S.S. Pegasus, a controversial ship that, in 2358, secretly tested a cloaking device. Pressman's controversial testing of cloaking technology while in command of the Pegasus resulted in a mutinous crew and the ship "phasing" partially into an asteroid. One crew member at the time, William Riker, supported his captain.
In 2370, Pressman used the Enterprise-D and Riker's loyalty to salvage the cloaking device aboard the derelect Pegasus, But Riker learned the truth behind his former captain's motivations, and Pressman was eventually arrested for his covert action.