Beverly Hills, CA --Here is some theory, science and investigative issues police must deal with is this killing of Hollywood publicist, Ronni Chasen . Someone could have searched for and recovered the empty brass ejected by a semi-automatic pistol but at night that seems unlikely. The reality is that the cops simply never determined the shooting location so they did not know where to look for the brass. Ballistic firearm identification science can be easy or impossible. In the case of revolvers there are only the expended projectiles. Soft lead that had been sent into flesh, bones and heavy clothing are often damaged beyond recognition. This is especially true for smaller caliber high velocity ammunition. Slower moving larger bullets suffer less damage and are more easily identified. Most of the modern center-fired ammunition have copper jackets covering the softer lead. This material is more likely to have identifiable rifling marks for the examiner’s microscope. With semi-automati...