In my ideal world, the official Law Enforcement Officer should have a good understanding of their legal system. I'll agree with you that college isn't the only way to get that understanding.
In Sweden you have to go to 'cop college' to become a cop. A 3 year practical and academic program (including at least 6 month on the job training) that teaches you how to be a cop. You cannot just show up with a random college degree and decide to be a cop.
I mean, is it even a useful way? Unless you major in pre-law, you aren't going to know more about the legal system than you got from high school civics.
If you want to be a detective you might value the post highschool education. Out of the ones I've known, they tend to have a criminal justice degree. They drive different vehicles, interact with people in different contexts, and may have different pay grades.
Many (perhaps most) police departments require new cadets to be patrol officers for N years prior to being promoted to Detective. Once promoted to the equivalent rank, you still need an opening on a unit and it can be competitive from what I gather.
