Wait a sec, Fairfax County, the county where I went to high school for a couple of years, is about 2 hours by road north of Charlottesville. (With traffic these days, a bit more?) About 100 miles as the crow flies, give or take a bit, and a bit more down route 29.
I am not sure why Fairfax County cops are operating out of their jurisdiction? (Was the helo on loan to the Virginia State law enforcement effort? I imagine there are a variety of inter departmental agency MOUs on stuff like that).
In any case, very sorry to see these folks lost while doing their duty.