If I was you, get your GED and sign up for the military. If your wanting to do criminal justice, let the military pay you to go to school, teach you some life skills AND take college classes that you can do w/ GI bill. Work as a LEO for the military till your term is up. Is a GED the best? Not exactly, but with military training and college to back it, it will work out the same.
Just dont life pass you up with neither one. If at all possible go back to high school and get a diploma even if it is from night school. Bad decisions (education, driving record, credit) at a young age, will haunt you for many years to come. Sacrafice everything when it comes to the rest of your life!!! G/L in these important decisions.