A Starfleet Academy cadet and member of the elite Red Squad who admits to Benjamin Sisko in the episode Paradise Lost that his unit sabotaged Earth's power grid under orders.
Cadet Riley Shepard is a member of Red Squad, an elite group of Starfleet Academy students, in the fourth-season episode Paradise Lost. Nog, newly arrived at the Academy and eager to join the squad, lets slip to Benjamin Sisko that its cadets were sent on a secret assignment on the night Earth's power relays failed.
Sisko summons Shepard and, by pretending to know more than he does and berating him for a botched job, gets the proud young man to defend himself. Shepard recounts how Red Squad was beamed to the planetary power system and disabled it, on orders passed down from Starfleet Command.
The admission shows Sisko that the blackout blamed on changelings was staged by Admiral Leyton to justify martial law, and Shepard's statement becomes the evidence he tries to put before President Jaresh-Inyo.