This is a VERY odd statement ("this time"), almost implying they goofed up before.. Russian fighter jets 'training' over U.S. territory? Wouldn't surprise me.
TWA 800?????
Where on this planet will you find a fighter pilot who is willing to fly loops over a city, in a Cessna, every night? Even if you issue a direct order, what the pilot is going to learn in such a mission that he hasn't learned in his first week of flight school?
As other comments indicate, this is a law enforcement operation ran by a TLA. If I were to guess, judging by absence of any ground activity, they are just testing new equipment.