When Rossi arrives at the unsub's crime site, there are two DC police SUV's there. But the site is supposed to be in Rockville, MD, which is out of DC police's jurisdiction. (DC police are not auxiliary units to federal authorities; they are strictly the local police of the District of Columbia.)
When the team deduces where the unsub is holding his latest victim (in a warehouse in Rockville, MD), Simmons says he and Reid are on their way, since they're already traveling between sites of interest. Rossi tells them he'll meet them there. However, Rossi is still at BAU headquarters in Quantico, VA, which is about an hour away. The unsub should have already murdered his victim by then, but the next scene show Rossi arriving before and murder is committed.