This is another luck based achievement. To become a Police Officer, you first need to choose not to go to college and just hope you pick this career. While you are a Police Officer, you can get $5,000 from any player that spins a 10 on the wheel, as they are speeding. This will come without really trying.
If you are having trouble, start a 4-player game and choose not to go to college with all the players. One of them should get Police Officer. If not, keep restarting until one does. Then just keep taking turns with all the players. It should not take long before one of your players spins a 10.