Download Elizabeth Funcheon 10/27/12 Term Paper – Part 3

Elizabeth Funcheon
10/27/12
Term Paper – Part 3
Firearms: Trajectory & Ballistics Analysis
While they have been used for sundry acts throughout history, firearms have become the
weapon of choice for most when committing a crime. Especially in contemporary American society,
firearms are used quite often and in a wide variety of criminal transgressions. In order to analyze the
scene of a crime in which a firearm was used, one must examine both ballistics and trajectory. Ballistics
refers to “the study of bullets and firearms”.1 Essentially, this is the examination of the actual bullet,
casings, and firearm in order to identify and match a particular firearm to a scene. Trajectory is a
“bullet’s path from the moment of discharge from a firearm until it comes to rest “. 2 Trajectory is an
integral part of evidence of a firearm scene because it can reveal the location of the shooter. It is the
compilation of this information that can allow one to understand the progression of a particular crime
scene.
The official study of ballistics has existed for nearly a century; the FBI Bureau of Forensic
Ballistics was established in 1923.3 While methods have advanced and progressed into modern age in
accordance with technology, many fundamental concepts still remain the same. The first step in
unraveling the truth of a firearm crime scene is to analyze any of the physical objects left behind, i.e. the
bullet, casings, and firearm. Once collected, these items must be examined for unique markings and
identifiers such as serial numbers, size of caliber, and brand.
A concept known as rifling, which is markings left on a bullet from a barrel of a gun, is essentially
a firearm fingerprint. When the trigger of a gun is pulled, the firing pin hits the base of the cartridge,
1
(Bertino, 2008), pg. 492
(Young, 2011), pg. 275
3
(Bertino, 2008), pg. 499
2
causing a spark, of which the bullet is then propelled in the barrel of the gun and sent spiraling
outward.4 It is that spiraling motion of the bullet that leaves microscopic striations from the barrel,
which are distinctive to each gun. The series of lands and grooves that remain give an investigator a
unique identifier, and therefore the ability to match against a particular firearm.
Cartridge casings can also be studied for unique markings. Essentially, there are three areas on
a casing of which to examine: firing pin marks, breechblock marks, and extractor/ejector marks.5 When
the firing pin comes in contact with the end of a cartridge, it leaves an indention. Similarly, when the
bullet is propelled forward, the casing is forced backward. This sends the cartridge into the breechblock,
creating yet another marking. On automatic or semi-automatic weapons, the casing is moved in and out
of the chamber via the extractor and ejector mechanisms, each leaving markings as well.
The weapon itself is the control that the bullet and casing are compared against. If an
investigator does not have the actual firearm, it would be nearly impossible to match to a particular
firearm unless the information was already stored in a database such as the National Integrated
Ballistics Network. Firearms are also manufactured and engraved with individual serial numbers.
Depending on state laws, that serial number may be logged into a database with an owner name. If a
firearm is recovered with the serial number intact, it is possible in some cases to trace it back to the
owner.
The other pivotal part of firearm forensics is the study of trajectory. While ballistics reveals what
was used in a crime, trajectory shows how. Bullet path and angle are calculated to show where the
shooter was in relation to the end point (either victim or object). Trajectory can be calculated using two
reference points—usually an entry and exit point. By examining a bullet hole a technician can use the
trajectory rods and measurements gathered from instruments such as angle finders, in order to
4
5
(Bertino, 2008), pg. 495-496.
(Bertino, 2008), pg. 496-497.
calculate trajectory. With laser technology, bullet path can be displayed visually by simply shooting a
laser from the bullet hole to the origin point.
When bullets come in contact with glass, they react differently than with other solid objects.
Glass is unique in the way that an investigator can determine the exact order in which the shots were
fired. Radial cracks emanate from the site of impact. Therefore, one can determine which shot came
first; “a radial crack will terminate on its own or when it collides with another crack”.6
Another important factor that must be taken into account when calculating bullet trajectory is
ricochet. A bullet will ricochet when it does not have enough velocity—resulting in a lack of
penetration. Ricochet can also occur with a person. If a bullet successfully penetrates a victim, it can hit
bone and ricochet throughout the body causing more damage.
The national database which has a record of bullets and casings, is the National Integrated
Ballistics Network (NIBIN). In 1999, the NIBIN was originated via an amalgamation of the National
Integrated Bullet Identification System and FBI’s Drugfire; NIBIN is the official database used by law
enforcement today7.
In recent years, the validity of some evidentiary techniques in firearm forensics has been
challenged. One of such techniques is the study of gunshot residue. This is the process by which an
examiner tests the hands and clothing of a suspect to see if they in fact contain gunshot residue. This,
however, does not prove a suspect fired a particular gun. It merely proves that they fired a gun.
Possibly the most controversial example of firearm ballistics and trajectory would be the
assassination of John F. Kennedy. On November 22, 1963, President JFK was shot and killed while his
motorcar travelled through Dealey Plaza in Dallas, Texas. The Warren Commission surmised that Lee
6
7
(Young, 2011), pg. 277.
(Division, 2012)
Harvey Oswald fired three shots from the Texas School Book Depository sixth floor window.8 The first
missed the 1961 Lincoln Continental convertible sedan entirely. The second shot—also known as “The
Magic Bullet”9—struck Kennedy in the back, passing through his body, into Governor Connally’s back
and through his chest, hitting his right wrist, and into his left thigh. The third and fatal shot struck
Kennedy’s head and killed the President.
Amongst the various alternate assassination theories, including ones such as the umbrella man
(shot from an umbrella handle of a suspected man seen in the Zapruder film), the three tramps (CIA hit
men), and the storm drain shooter (shooter hidden in a storm drain), the most popular remains the
grassy knoll shooter.10 The theory essentially postulates the idea that there was an alternate shooter on
the grassy knoll. Many witnesses claimed to hear the shot coming from that direction rather than from
the book depository.
Anatomical Surrogate Technologies, a firm which specializes in manufacturing anatomic human
surrogates, created Kennedy and Connally doubles to be used in a reenactment which would affirm the
Warren Commission Report of Oswald as the only shooter and assassinator of President John F.
Kennedy. They used actual human models that were comparative sizes to the President and Governor
and created plaster castings that they poured fiberglass resin in to make a mold. They used these block
torsos to create outer shells. Information was then entered into a database to calculate the approximate
size of the skeletal torsos of both men, and then used silicone molds to recreate the bones. A shammybased “skin” was hydrated with oils to perform like actual skin. The skin was then layered with a muscle
8
(Erickson, JFK: Death at Dealey Plaza (Unsolved History: Season 1, Episode 12), Feburary 2003)
(Erickson, JFK: Beyond the Magic Bullet (Unsolved History: Season 3, Episode 2), November 2004)
10
(Kamarudin, 2012)
9
replicate gel. The model rib cage was placed into the muscle/skin solution and set for ten hours at thirtynine degrees Fahrenheit.11
Using a platform consisting of tables for the simulated torsos to rest on, the team placed a
marksman sixty feet in the air—the calculated height of Oswald’s six-story perch. The sniper used a six
and a half millimeter Carcano Model 91/38 bolt action rifle and 6.5x52 millimeter Cartuccia Modello
1895 rimless cartridge ammo—the same as Oswald’s. After an initial test shot, the marksman fired at
the torsos of the fake President and Governor. The test “magic bullet” struck the first torso, into the
second, and into the fake wrist. The bullet did not have enough velocity to penetrate the replicate thigh;
instead, it ricocheted off into the nearby brush. After the experiment, the team had the items CAT
scanned which revealed that their test bullet fractured two ribs instead of one. This caused the bullet to
slow down and become warped and deformed, therefore, not giving it the power it needed to imbed in
the thigh. They concluded that their evidence substantiated the premise that Oswald was the lone
assassinator of President Kennedy.12
While this experiment was a good attempt at showing the trajectory of the magic bullet, it did
not precisely recreate the scene and take all factors into account. First, their model “car” did not move;
the platform remained stationary throughout the entire presentation. Kennedy was assassinated in a
car, therefore, the platform should have been moving at the exact speed as the Lincoln. The sniper was
also suspended in the air by a bucket which was not a stable permanent surface such as the building
Oswald was in. There is also the fact that their experimental bullet did not become lodged in the pseudo
Connally’s thigh—it deflected.
It is common knowledge that it is harder to hit a moving target. If the platform was not moving,
it made it exponentially easier for the sniper to hit his targets precisely where he needed. The shot in11
12
(Geller-Wolf, 2008)
(Geller-Wolf, 2008)
and-of itself was a difficult one to make without adding the complication of the moving car. When you
add the factor of the experimental sniper’s location in a movable bucket perched sixty feet in the air,
this can account for some of the error with the experiment. His perch was rocking with the wind which
made it harder for him to accurately line up his shot. As already established, the bullet did not enter the
model thigh because it ricocheted of two ribs instead of one. This slowed the bullet so that it did not
have enough velocity to penetrate the thigh. Even though there were errors in their experiment, it does
not invalidate their findings.
The actual positioning of Kennedy and Connally has been a longtime debate. What most people
do not know is that Connally was seated on a jump seat. That meant that he was located approximately
six inches to the left of Kennedy, with his body turned to the right, and roughly three inches lower than
Kennedy.13 Taking into account his seating position, it should theoretically line up if you were to
calculate a trajectory line from Oswald’s location on the sixth floor of the book depository to its end
point in Connally’s thigh.
Firearm forensic technology has progressed over the years into a more stable and reputable
form of evidence. While some practices are still controversial and not widely accepted, such as gunshot
residue, most are a valuable tool in solving crimes. Trajectory calculations are quite nearly indisputable if
calculated precisely; they certainly open an additional facet of an investigation that would not be
available without this technology. Ballistics are becoming more reputable as the NIBIN database grows
to include more pieces, evidence will become more reliable due to a larger base of information. If this
advanced technology had been readily available and used in the 1960s, there might not be so much
controversy and radical conspiracy theories surrounding Kennedy’s assassination.
13
(Erickson, JFK: Death at Dealey Plaza (Unsolved History: Season 1, Episode 12), Feburary 2003)
Bibliography
Bertino, A. J. (2008). Forensic Science: Fundamentals & Investigations. Mason, OH: Cengage Learnine.
Division, A. P. (2012). National Integrated Ballistic Information Network (NIBIN). Washington, DC: Bureau
of Alcohol, Tobacco, Firearms and Explosives.
Erickson, R. (Director). (Feburary 2003). JFK: Death at Dealey Plaza (Unsolved History: Season 1, Episode
12) [Motion Picture].
Erickson, R. (Director). (November 2004). JFK: Beyond the Magic Bullet (Unsolved History: Season 3,
Episode 2) [Motion Picture].
Geller-Wolf, S. (Director). (2008). JFK: Inside the Target Car [Motion Picture].
Kamarudin, Y. (2012, December 9). Environmental Graffiti. Retrieved from 10 Most Incredible JFK
Assassination Theories: http://www.environmentalgraffiti.com/news-most-incredible-jfkassassination-theories?image=0
Young, T. (2011). Crime Scene Investigation: The Forensic Technician's Field Manual. In P. Otrmeier.
Upper Saddle River, N.J.: Pearson Education.