Why Cops Are So Dirty

I always have been wondering why cops are so crooked. Its just not right how they can just plant things on people and use it as evidence on there case. It has happened to me before at the age of 14 years old there was drugs and a gun in the car. When I had gotten pulled over I had removed all the crack from the car through it in the bushes it was my x-boyfriends he was also in the car, then after the cop had searched the car the drug popped up in the middle of the car in the compartment. I went straight to detention do not pass go and do not collect your $200. The case is old and I can honestly say that I have learned my lesson.