Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives
Abstract
The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano, 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in Mannlicher-Carcano bullet lead, and the 5-60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 900118
- Report Number(s):
- UCRL-TR-224202
TRN: US200709%%537
- DOE Contract Number:
- W-7405-ENG-48
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALLOYS; AMMUNITION; ANTIMONY; CASTING; COPPER; GRAIN BOUNDARIES; PROCESSING; REFINING; SAMPLING
Citation Formats
Randich, E, and Grant, P M. Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives. United States: N. p., 2006.
Web. doi:10.2172/900118.
Randich, E, & Grant, P M. Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives. United States. https://doi.org/10.2172/900118
Randich, E, and Grant, P M. 2006.
"Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives". United States. https://doi.org/10.2172/900118. https://www.osti.gov/servlets/purl/900118.
@article{osti_900118,
title = {Proper Assessment of the JFK Assassination Bullet Lead Evidence from Metallurgical and Statistical Perspectives},
author = {Randich, E and Grant, P M},
abstractNote = {The bullet evidence in the JFK assassination investigation was reexamined from metallurgical and statistical standpoints. The questioned specimens are comprised of soft lead, possibly from full-metal-jacketed Mannlicher-Carcano, 6.5-mm ammunition. During lead refining, contaminant elements are removed to specified levels for a desired alloy or composition. Microsegregation of trace and minor elements during lead casting and processing can account for the experimental variabilities measured in various evidentiary and comparison samples by laboratory analysts. Thus, elevated concentrations of antimony and copper at crystallographic grain boundaries, the widely varying sizes of grains in Mannlicher-Carcano bullet lead, and the 5-60 mg bullet samples analyzed for assassination intelligence effectively resulted in operational sampling error for the analyses. This deficiency was not considered in the original data interpretation and resulted in an invalid conclusion in favor of the single-bullet theory of the assassination. Alternate statistical calculations, based on the historic analytical data, incorporating weighted averaging and propagation of experimental uncertainties also considerably weaken support for the single-bullet theory. In effect, this assessment of the material composition of the lead specimens from the assassination concludes that the extant evidence is consistent with any number between two and five rounds fired in Dealey Plaza during the shooting.},
doi = {10.2172/900118},
url = {https://www.osti.gov/biblio/900118},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Aug 29 00:00:00 EDT 2006},
month = {Tue Aug 29 00:00:00 EDT 2006}
}