The police need a professional spokesperson tho...
If/When the sniper attacks again he will probably be caught. I have to believe that by now the LEOs have a plan to freeze all traffic in the area of the shooting within a few minutes after it happens. Then a car to car search begins. Of course this requires one helluva lot of police manpower but if done right they would stand a good chance at catching this POS.
And if the sniper chooses to start killing outside the greater DC area the Creep is most likely operating in unfamiliar territory which also increases the chances he will make a mistake or leave a trail.