There are lots of opportunities, but you need to be willing to either sacrifice or know how to network.
The DA openings are almost always in rural areas because the prosecutors who cut their teeth in those rural areas are the ones with the experience necessary to get the more highly coveted metro-area jobs. That's pretty much how it works everywhere. Some possible exceptions are positions in solicitor's offices or positions that handle only misdemeanors. Barring this, you need to be willing to spend a few years getting experience in a more rural office and wait for an opportunity to open up in a metro office.
As for defense firms, start networking. These firms almost never interview on campus because they don't care to pay the fees charged by schools for the privilege of getting a room for OCI. Instead, start going to local bar events, especially those for the criminal division.