Marienfield was born on July 12, 1989, in Sacramento, California, along with his older brother, Damien. After Chalk rose to power, and Marienfield realized what he would do to the country, he founded the Revolution and began opposing Chalk.
Marienfield is arguably the best companion Rico has. He has good aim, doesn't rush into battle, has alot of HP, drives a fast car, uses the CS Desert Storm, and never leaves Rico's side. Marienfield also has a "rage mode", in which he does much more damage when his health is at 43 points or lower. There is no reason given as to why this happens, though he usually tells others "he ain't got time to bleed" as a justification. Marienfield is very emotional, crying for long periods of time in sintances such as Jonas Alvarez's or his brother's death. Mika has feelings for Marienfield, although he is completely oblivious to it untill she directly tells him at the end of the game. They kiss, and the credits roll.
- Marienfield's "ain't got time to bleed" line is a a reference to the movie Predator.