My thought is that the bikers, to the extent they were armed with guns, were probably armed mostly with 9 mm, .40 cal., .38, & .357 magnum weapons. Rounds from all of those make very different wounds than .223 & .556 NATO rounds fired from riles. IOW, determine the types of round that inflicted the fatal wounds, and determining who fired those rounds becomes pretty easy. Could be difficult for the LEO types.
I swear .223 and .556 are louder than my .308’s.
Either that or I am just surprised how noisy a .22 can be coming out of a 18” barrel, propelled by 5 x’s as much powder.
/S....obviously
I’ve been wondering that myself...