Sheriff Dept flying jobs. Most require you to be a LEO first. So unless you are willing to go the LEO route, then hope they give you a slot in their aviation department, that jobs a long shot. Plus, pay is hardly above what an LEO makes, and depending on the sheriff and politics, if a new sheriff is elected, your pilot job may go to one of his people and you are back in a patrol car.
DEA. Yep, they have pilot jobs. One must qualify as a DEA Agent first, so there are several requirements for federal law enforcement. Then, a new hire DEA pilot doesn't get his pick of duty locations, and goes to the bottom of the list. Many of those locations are undesirable to live, and may require being assigned there for years before having enough seniority to move up. And inter agency politics come into play. Just because you have seniority, doesn't mean is an opening in a popular location comes open you will get it.
Corporate jobs? That runs the gamut, but usually takes networking. While some corporate work is good, on the flip side some are really bad. Recently had an associate that took a corporate position in a city where he really wanted to relocate. He sold his home, moved the wife and kids halfway across the country and he thought he found his perfect situation. 3 months later they sold the airplane and laid him off. He now flies for an airline.
Yep, there are other flying jobs outside of 121. I've known a few that went that route, such as ISR. ISR pays really well, but requires long periods of being gone, plus the entry requirements can be challenging and probably on par with getting into 121.