In urban environments like cities, more crimes occur, which equal the need for more Forensic Scientists. However, how much that city is invested in their labs is the true issue. I know for a fact that even in New York City, with their large laboratories and staffs, they have a large backlog of evidence to examine, and their budget can hire only so many people. Not to mention the inner politics in such a work environment can be taxing on your mental health and productivity. Competition for a forensic scientist is also extremely high due to low turnover.
Suburban areas do not have as much crime, but that doesn't mean it is nonexistent. Some counties can afford to fund a forensic lab, but a lot of suburbs do not and often send their evidence to be analyzed elsewhere in the state where there are labs. The same can be said for rural areas, where populations are low, resulting is less funding for any laboratories.
I, too, am learning as I go, and have decided to get some practical experience working in non-forensic science labs to pad my resume. Most Forensic science labs require years of experience before taking in new employees.