Epidemus

Commodore Epidemus is a Starfleet officer in the 25th century. In 2410, he uncovered strong evidence that James Copper had murdered his former commander Qatanmek during the Battle of Pellia. Epidemus challenged Copper's original testimony that he had perished when a Pellian ship scored a direct hit on the bridge, causing the entire compartment to depressurise. Epidemus' evidence was closed circuit footage of the bridge during the attack, showing Copper clearly shooting Qatanmek in the back and prising the command pips off his body. His evidence was refuted however when none other than Qatanmek walked into the courtroom and told the truth, albeit in semi-corporeal form.