More PC BS for the gun-grabbers. There is NO indication the killer is using an "Assault-type weapon." MANY bolt action and hunting style repeaters are made in .223. The killer has not fired more than one shot in each murder, which indicates a bolt action hunting rifle if ANYTHING. But a bolt action hunting rifle wouldn't do the gun-grabber movement as much good as an "Assault-type weapon."
My first thought when they id'd the .223 from ballistics was "bolt varmint gun".
The only other evidence they have - aside from projectile fragments- is the spent case, which may have extractor/ejector marks that skew it towards a semiauto, or they may simply be rationalizing that nobody would eject a spent case from a bolt gun if they only intended to fire one shot. Either way, the evidence for semi auto appears weak at best.
If the case is bogus, we're back to anything goes.
You are exactly right. I also understand that a shell has been found at only one site (next to the planted tarot card). So unless the shooter has a brass-catching net, or is firing from inside the truck, or is running after flying brass, he's not shooting a semi-automatic.
(If he is using an assault rifle, he's not taking advantage of its mechanism, since he's shooting only once. But of course, a lone sniper would find such a weapon more reassuring in case he faces armed counter-attack.)