Logan Sheppard was a GDI Commando during the First Tiberium War. While originally intended to be the player character in Command & Conquer: Renegade, he was relegated as the game's tutorial guide. The role of the player character was filled by Nick "Havoc" Parker.
Lieutenant Logan Sheppard was the son of GDI General Mark Jamison Sheppard. Logan followed in his father's footsteps and joined GDI. Given that he was the son of a general, he had to work hard to prove that he did not get his position in the GDI due to nepotism.
He was an excellent marksman with a variety of small arms, ranging from silenced pistols to sniper rifles, a skilled saboteur and a very agile man with acrobatic skills. Unlike captain Nick Parker, Logan preferred stealth and sabotage over direct engagements, even though he was a capable foe in regular combat.
During the First Tiberium War against Nod, Logan participated in numerous operations against the Brotherhood, including the destruction of a crucial Nod airstrip. He occasionally ran refresher courses for GDI commandos.
Logan Sheppard was intented to be the protagonist of Command & Conquer: Renegade before the original concept was changed. He is featured in the first trailer for the game as well as numerous beta screenshots and the tutorial as the guide and is, arguably, much more refined and subtle than Nick Parker, the eventual protagonist.
Havoc was supposed to repeatedly chastise Logan in the tutorial for the fact that his father is a GDI general.
However, while the protagonist was changed, Logan's character wasn't cut - instead, he serves as the instructor in the Renegade tutorial.
His model is available in multiplayer, on servers with the extras variable enabled. To access him, one needs to hold ALT while selecting the characters menu. Logan is equipped with the standard pistol and remote C4 as well as a sniper rifle.