Unlock Ghetto City:
Hold L1 + R1 at the CompStat/Map screen and press X, Square, X, Triangle(3).

Unlock Fights:
Hold L1 + R1 at the CompStat/Map screen and press Square(2), Triangle(2), Square.

Unlock Street Races:
Hold L1 + R1 at the CompStat/Map screen and press Triangle(2), X(2), Triangle.

While you are on the CompStat/Map screen hold down the shoulder buttons before entering the following codes

Ultra Easy Mode:
Circle, Square, X, X, Triangle and Circle

Unlimited Endurance:
Circle, Square, x, Square, X and Circle

Unlimited Ammo:
Circle, Square, X, Square, Square and Triangle

Double Damage:
X, X, Square, X, X and X

Get a Million Dollars:
Square, Square, Triangle, Square, Triangle and Square

Super Cop:
Triangle, X, Triangle, X, Triangle and Triangle

Unlock Redman Gone Wild Mini-Game:
Triangle, X, X, Circle, Triangle and Square

Unlock Redman Gone Wild Mini Game:
Complete the Game 100%