In the original concept for Louis, he was a homeless man with a dirty jacket, a scruffy beard, and a bandaged head injury. Later, he was "cleaned up" somewhat and became an assistant manager at a electronics chain store. In the final build, Louis is the Junior Systems Analyst in his company's IT department.
The following is an official description of Louis written by Valve.
"Louis had been working up the courage to quit his job as Junior Systems Analyst at his company's IT department when a virus showed up and downsized the world. Now Louis has a new set of goals (live long enough to succeed) and a new set of tools (guns, sharp objects) to help him achieve them. With any luck, he'll figure out how the new management operates before they get a chance to murder him."
Louis's head appears in the Steam version of Mevo and the Grooveriders.
In the Cold Stream announcement Valve revealed that Louis will appear as a skin in the XBLA version of Minecraft.
Louis is a playable character in the Cold Stream DLC, which features the four classic maps from the first Left 4 Dead.
- Louis' design may have been based off the title character from Shaun of the Dead as their clothing is almost identical and Shaun worked as an electronics store employee.
- Louis plays Counter-Strike, Team Fortress 2, and possibly Half-Life (he originally had a line for picking up a crowbar where he said it made him "feel like Gordon Freeman", but it was cut).
- Louis is an expert on firearms and used to visit a rifle range before the outbreak.
- In the Passing, Louis names a Tank kill in honor of Bill who most likely held back the Infected while Louis, who is crippled at the time, and the other Survivors made their escape.
- Louis is often shown carrying pistols in promotional artwork but favors Assault Rifles in-game and wields the Heavy Machine Gun in The Passing.