Ballistic Forensics for Lawyers

Seiden

I often get calls from other lawyers asking me for the name of a “ballistics expert.” Invariably, before I can make any recommendation at all, I must ask them to describe the case.We are all conditioned to the world of forensic ballistics on television, where a medical examiner walks up to a body, quickly eyeballs it and says, “He was shot with a Webly-Fosberry Automatic Revolver, caliber .38.” This is pure fantasy.There is, however, a lot of information that can be gleaned from any firearms discharge, providing the practitioner knows what questions to ask and who to ask them of.Let’s examine the different types of “forensic ballistics.” The first area is internal ballistics. Internal ballistics describes what happens from the instant the cartridge is discharged up until the time the projectile leaves the barrel. If the projectile (or fragments of it) is recovered, often times the caliber of the weapon can be determined as well as the make.Each barrel imparts specific characteristics to a projectile as the bullet engages the rifling in the interior of the barrel, which causes the bullet to spin. This rifling engraves the projectile with distinctive patterns and by matching the width and diameter of the lands and grooves, as well as the twist of the rifling, the manufacturer can often be determined.

There have been some recent challenges to the long held presumption that a bullet can be identified as having been fired from one particular firearm to the exclusion of all others. If that is what your adversary is alleging, don’t hesitate to file a Dowe or Frye challenge and demand a hearing.

Cartridge casings, especially those ejected from semi-automatic or automatic weapons can often be tied to the weapon in question by a firing pin imprints, breach face imprints and extractor or ejector marks on the cartridge casing. The principles involved are identical to other tool mark evidence, where it is alleged that individual tools (or weapons) produce individual characteristics that authenticate the premise that the casing was ejected from a particular weapon. This could be challenged as well.

The next area of ballistics are external ballistics. External ballistics involve what happens once the projectile leaves the muzzle of the weapon just prior to striking the target. If proving the path of the bullet is important to your case, you don’t need a “ballistics expert,” but rather an expert in the area of shooting reconstruction.

A variety of things can be learned from a competent shooting reconstructionist, including the trajectory of the bullet, any intervening objects or deflections due to the bullet having struck something, the location of the person having fired the shot and in some instances, the sequence of the shots that were fired.

The last area of forensic ballistics is known as terminal ballistics. Terminal ballistics involves the science of what happens when a person is struck by a bullet. In other words, it reconstructs what happens inside a shooting victim and can both inculpate or exonerate the shooter depending upon the individual circumstances.

Several years ago, I tried a murder case where the victim was “shot in the back” after a confrontation with his landlord. The angles of the bullets inside the body were widely divergent, one striking the left shoulder, one more or less in the center of the back and the third through the right side of the torso. When reconstructed, the testimony was that these angles were consistent with the decedent swinging a tire iron at my client with the revolver being fired in rapid succession as he followed through with the swing. The result was a not guilty verdict.

The last area that a lawyer should be aware of is not “ballistics”, but how the firearm in question operates, what sort of safety mechanism are there? Was there some sort of an internal or mechanical defect that caused the firearm to discharge? Does the firearm in question have a generic history of accidental discharge?

As an example some years ago, a police officer after a motor vehicle chase tapped his pistol on the passenger side glass of the vehicle in order to attract the driver’s attention and get her to open the door. When the firearm was tapped against the window, it discharged, killing the driver. The police officer swore that he did not pull the trigger or intentionally shoot the decedent.

A careful analysis of the firearm showed that the inertia of the firing pin overcame the resistance of the firing pin spring quite easily and tapping the loaded pistol against a hard object, such as glass, would cause the firearm to discharge more times than not. As a result, the officer was exonerated and firearms of that design were subsequently disapproved by the department for duty use because of that defect.

In Summary, look at your shooting case carefully and analyze what it is you are trying to prove or disprove. Rather than seek out a generic “ballistics expert,” look for someone who has specific expertise in the area of ballistics that are relevant to your case.