Go to college. Believe it or not, a lot of police officers do have degrees in things such as criminal justice. They aren't high school kids that decide to become police. In fact, you need to be 21 before they'll even consider you. You'll also want to be fit. The police have a very [i]interesting[/i] physical fitness test. It actually involves simulations that have to be completed in a certain time period too. After this point you're going to want to look up your local police academy. That's when you really 'start.' I think it's like half a year of training. At that point there are a bunch of tests both physical and mental. Assuming you pass, you just need to apply at a police station and get accepted!