The police have incorrectly speculated on the weapon type and the ignorant media with an agenda is aiding them in deamonizing all rifle types and those that own them.
Known facts: several people have been shot from a distance by a high velocity small caliber weapon with no witnesses of any of the shooters. All the of the victems appear to be randomly chosen and hit with a single shot. The D.C. metro area is being terrorized by the shooting as it continues day and night with no known shootings over the weekend. The activity may be from low level trained shooter(s) to a skilled marksmen but can be classified as a sniper because distance and or concealment thus far has prevented identifying any suspects which have restrained from taking a second shot and avoided detection in the target area. No evidence is left behind including shell casings. If a semiauto weapon is being used they are picking up the spent case. It is more likely to be a bolt action rifle with no shell being ejected and possibly with a suspressed barrel.
Boy howdy, you got that right. The cartridge they have showed and identified as a .223 appears to be a .308. One "expert" this morning concluded we should be looking for a moose hunter. I wouldn't hunt moose with anything smaller than a .300. I also agree with your BAR assessment since not one casing has been found.