A: You have to attend and successfully graduate from a police academy to become a cop. You must at least be 21 years old, when you are officially inducted into the police force. You must be a permanent citizen of the United States of America. You must graduate high school preferably with a GPA of 2.0 or above.: To be a police officer, one has to have the right aptitude as the job comes with a lot of responsibility. If you have a high school degree you can get entry level job positions. Some law enforcement agencies may require a bachelor's degree in criminology, justice system or related area.