Hold down the L1+R1 shoulder buttons while you are on the CompStat/Map screen before pushing the following buttons:

Square, Square, Triangle, Square, Triangle and Square

Alright, if you want to get the music keep going then follow these steps:
1. First get like a crime alert or wait for it
2. Go inside the building and through the door
3. Solve the crime
4. When you go outside pause the game
5. Unpause

If you followed these steps correctly, you'll hear the crime alert music still going.

Note: To disable it, solve another crime alert. The only sad thing as that, if a crime will spawn the music ends even if it's unresolved or resolved =( (unless you do a cheat to get rid of crime).

This cheat is easy to do just go to the compstat and hold L1 and R1 then let go and in half a second push the right D-pad button and hold L1 and R1 again.
You will be in the music player if you see the map in the back let go of L1 and R1 and push left and there you go the Debug Menu.

(NOTE) some things in the Debug Menu might make the game crash so before go to the debug menu make sure you save

Enjoy

If you are tired of police.no worries.first activate (supercop) cheat then kill
2 or 3 cops then let the cop kill you.they will handover you to the police mam.then beat crime patrol and remember. Don't change you're cloths .if you change you're police cloths they will again kill you.don't change your police cloths so cops will never harm or kill you.enjoy gaming tcny

If you go into a restront you can eat food and it puts your health were it should be!

To get easy career points go into any car dealer shop and frisk everyone in it 9/10 times you'll get evidence
So keep going back.

At the CompStat/map screen, hold L1+R1 and enter the following cheats:

Infinite Ammunition: circle,square,x,square,square,triangle.
Infinite Endurance: circle,square,x,square,x,circle.
$1 Million: square,square,triangle,square,triangle,square.
Super Cop: triangle,x,triangle,x,triangle,triangle.
Easy Mode: circle,square,x,x,triangle,circle.
All Music Tracks: circle,square,circle,square.
Fights Open: square,square,circle,circle,square.
Races Open: triangle,triangle,x,x,triangle.
Puma Tracksuit: triangle,x,circle,square.
Double Damage: x,x,square,x,x,x.
Redman Mini-game: triangle,x,x,circle,triangle,square.
City Crime Gone: x,square,x,triangle,triangle,triangle.
Marcus With No Limbs: circle,triangle,square,x,square,x.

Get your car and throw away your nightstick now open your boot and you can equip 2 big meele wepons happy gameing

Goto the city map and press UP,RIGHT,DOWN,LEFT,UP,X

Im pretty sure this is the right thing,because I haven't played the game in a while.

First thing go to the Comp-Stat/Map screen, then hold L1 + R1 this will open up a window for you enter the codes.

Infinite Ammunition
Circle, Square, X, Square, Square, Triangle

Infinite Endurance
Circle, Square, X, Square, X, Circle

$1 Million
Square, Square, Triangle, Square, Triangle, Square

Double Damage
X, X, Square, X, X, X

Easy Mode
Circle, Square, X, X, Triangle, Circle

Super Cop Mode
Triangle, X, Triangle, X, Triangle, Triangle

Fights Open
Square, Square, Triangle, Triangle, Square

Street Races Open
Triangle, Triangle, X, X, Triangle

All Music Tracks
Circle, Square, Circle, Square

Puma Shoes Costume
Triangle, X, Circle, Square

Redman Gone Wild Mini-game
Triangle, X, X, Circle, Triangle, Square

Ghetto City (the City will be all red with crime)
X, Square, X, Triangle, Triangle, Triangle

Zombiefied Mode
Circle, Triangle, Square, X, Square, X
Note: blows of arms and legs the first time enter. Second time enter you only left with torso.

Go to the comp stat/map screen.Then hold L1 and R1and enter.
Triangle, X, X, Circle, Triangle, Square.

Go to the comp stat/map screen.Then hold L1 and R1and enter.
Circle, Square, X, Square, X, Circle.

Go to the comp stat/map screen.Then hold L1 and R1and enter.
Circle, Square, X, Square, Square, Triangle.

Go to the comp stat/map screen.Then hold L1 and R1and enter.
Circle, Square, X, X, Triangle,, Circle.

Go to the comp stat/map screen. Then hold L1 and R1 and enter.
Triangle, X, Triangle, X, Triangle, Triangle.

Go to the comp stat/map screen. Then hold L1 and R1, and enter
Square, Square, Triangle, Square, Triangle, Square

Go to the comp stat/map screen. Then hold L1 and R1 and enter.
X, X, SQUARE, X, X, X.

To unlcok all the music songs go to the map screen and hold all the shoulder buttons, then press:

circle,sqaure,circle,sqaure

To unlock the puma outfit at the puma store: go to the map screen hold all the back buttons and press: tirangle,X,circle,square.

To execute the cheats access the compstat menu and hold down L1 and R1

Money: Square Square Triangle Square Triagle Square

Ammo: Circle Square X Square Square Triangle

Endurance: Circle Square X Square X Sircle

'Dubble Damage: X X Square X X X