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-automatic firearms, examiners get a second bite at the apple, so to speak. They have the projectiles to compare but also the ejected shell casings that also have their own characteristics.
Some criminals will recover all the empty casings before the leave the scene or they can employ something called a brass catcher that makes searching for the empty brass unnecessary.
Result possibilities are that the items submitted for identification are:
1. Inconsistent and excluded as having been fired from the weapon
2. Consistent with being fired from the weapon
3. Consistent with and having been fired by the same weapon.
It is much easier to rule projectiles and shell casings out than make a match that is consistent to a scientific certainty as having been fired by the same gun.
Because of the delay and confusion in the Chasen case I suspect that there were only enough similarities in the comparisons for police to draw conclusions, but would not be surprised to know that the certainty is significantly less to 100%. Remember they don’t have to prove to a jury in any courtroom that this was in fact the same gun.
I don’t know the make or model of the gun nor the caliber and type of ammunition used in the Chasen murder or the Smith suicide.
Had police found the actual scene of the Chasen shooting it’s most likely they’d have recovered some or all of the expended brass. There is an additional possibility and that is the gun was fired from a vehicle and the brass stayed inside that murder car. If the killer put his gun and arm out the window there would have been brass hitting the asphalt.
I can’t really imagine anyone that just fired those deadly shots scrambling around in the dark trying to recover the empty brass.
Here are pictures of two S&W 940 9MM revolvers.
Those little revolvers use full moon clips to hold the five rounds so these rimless cartridges don’t fall through the cylinder.
I don’t think that this or the even more rare Ruger 9 MM revolver were used in this crime. These guns do not eject brass like semi-automatic pistols.