At some point prior to 2262, Clemens served with fellow Earthforce officer Elizabeth Lochley. During the Civil War, Clemens held the rank of Major and was in charge of the prison system on the Beta 7 colony. There, he was involved with the murder and torture of dissidents on Beta 7 and elsewhere. After the death of President Clark, Clemens became wanted and went underground in order to escape apprehension.
Blaming John Sheridan for destroying his life, career and family, Clemens had nothing to lose. He became determined to kill Sheridan during his swearing-in as President of the then newly founded Interstellar Alliance. He found and killed a Ranger, then left his body in a commercial stasis bubble near Babylon 5. This would rattle security on the station and possibly change plans for Sheridan's inauguration. Drawing from his experience as a trained infiltrator, he disguised himself as a Gaim ambassador, who he killed, to attend the ceremony, however, he was prevented from shooting Sheridan by one of the rogue telepaths, Simon, that had just arrived on the station. He escaped and managed to steal one of the station's Starfuries and, coming around to the observation deck, threatened to shoot Sheridan from space. Unbeknownst to him, he was pursued by Michael Garibaldi sneaking up on him in a Starfury. His ship was grappled and taken away from the station, then destroyed by the station's defenses.
- His Earthforce record gives his serial number as "8910290-SOL-2" and shows that he became a qualified Starfury pilot on the 17th of July, 2249.