PSC482G, Spring 2000
Answers to Assignment 14
Warren Commission Report 5
(N.B. This assignment is for your guidance only. It need not be turned in.)
Read: Warren Commission Report Appendix X (pp. 547–597).
Answer these questions (briefly):
1. How do bullets pick up traceable markings as they are fired from a rifle? The sides of the bullet become engraved with the distinctive irregularities of the rifle barrel, as well as with its rifling pattern.
2. How do cartridge cases behave when ejected from a Mannlicher-Carcano rifle of the type used in the Depository? They fly out at nearly right angles to the barrel and at least 80–90 inches. Were the actual locations of the three cartridge cases found in the “sniper’s nest” consistent with this behavior? Yes. The cases were to the right of the barrel if it had been aimed through the SE window.
3. To what extent were the bullets retrieved from Officer Tippit’s body traceable to Oswald’s Smith & Wesson revolver? All four retrieved bullets were consistent with the revolver. Depending on the expert, 1/4 or 0/4 came from the revolver. More importantly, all four expended cartridge cases found in the bushes nearby were traced to his revolver to the exclusion of all other revolvers.
4. What is a paraffin test? The paraffin test looks for nitrate on the skin to see if the person has fired a weapon recently. Warm paraffin picks up impurities, including nitrate, from skin and pores. Diphenylamine or diphenylbenzidine reacts to form a blue color if nitrate is present. What were the results of Lee Harvey Oswald’s paraffin tests? Both of Oswald’s hands were positive, but his right cheek was negative. What conclusions can be drawn from these results? No conclusions can be drawn because test is unreliable—it gives both false positive and false negatives: nitrate can get on the skin in other ways, and lack of nitrate does not necessarily mean that the person hasn’t fired a weapon recently.
5. Did Lee Harvey Oswald actually order the Mannlicher-Carcano rifle and the Smith & Wesson revolver that the Commission linked to him? Yes. Outline the reasoning behind your conclusions. The handwriting on both order forms was identified as Oswald’s. Less significantly, it was delivered to his post office box.
6. Describe the penetrating power of a WCC/MC bullet in relation to other bullets. Extreme penetrating power, even greater than a NATO M-80 bullet fired from the M-14 rifle. Can a WCC/MC bullet pass through two human bodies? Yes, because it retains substantial velocities after one body. It can pass through four linear feet of pine board.
7. How did the Army’s Edgewood Arsenal simulate Kennedy’s neck wound? They constructed an artificial neck from sequential blocks of gelatin and two sets of animal meat and covered it with animal skin on each side. The thickness of the whole thing was set to match that of Kennedy’s neck, which was estimated at 13 ½ to 14 ½ cm. They then shot the combination with the actual weapon. How much velocity did the WCC/MC bullets lose in passing through the simulated neck? Less than 150 feet per sec from the impact velocity of 1900 feet per sec. Was the bullet still stable when it emerged? It retained most of its stability, and created an exit hole that was only a bit larger and more oval than the entrance hole. In fact, tests showed that WCC/MC bullets would pass through 54 cm of gelatin before beginning to curve (i.e., becoming unstable).
8. How did Edgewood simulate Connally’s chest wound? They shot a large animal with the actual weapon. What were the effects on the bullet and the simulated chest? The bullet lost <250 feet per sec. The animal’s rib was fractured very similarly to Connally’s. The bullet that passed through the animal was more flattened than CE 399, however. What can be concluded about the bullet that entered Connally’s chest? Could not have been pristine, or else it would have been damaged more than CE 399 was.
9. How did Edgewood simulate Connally’s wrist wound? Animal “bone structures” were shot. What were the effects on the bullet and the wrist? Bullet lost <100 fps. Nose flattened. Bone damage resembled Connally’s, but more severe. What did these tests show about the bullet that damaged Connally’s wrist? It could not have been pristine.
10. How are different kinds of fibers differentiated under the microscope? Color, diameter, and shape. How could fibers still be found on the rifle after it had been handled and tested? Small cluster of fibers had caught on irregularity of rifle’s metal butt where it joins the wooden stock. What was concluded about the origin of these fibers, and how incriminating was it to Oswald? Fibers matched Oswald’s shirt, but may have come from an identical one because many such shirts existed.