NCJ Number
67232
Journal
Journal of Forensic Sciences Volume: 25 Issue: 2 Dated: (APRIL 1980) Pages: 374-379
Date Published
1980
Length
6 pages
Annotation
CONCENTRATED NITRIC ACID COMPLETELY REMOVES THE COPPER JACKET FROM JACKETED BULLETS WITH NO CHANGE IN THE COMPOSITION OF THE BULLET.
Abstract
OFTEN, CRIMINAL INVESTIGATORS MUST COMPARE ELEMENTAL COMPOSITIONS OF BULLETS OR BULLET FRAGMENTS RECOVERED FROM A WOUND WITH BULLETS POSSESSED BY CRIMINAL SUSPECTS. HOWEVER, SEPARATING COPPER JACKETS FROM BULLETS TO BE ANALYZED BY DRILLING OR CUTTING CAN ALTER OR DESTROY THE COMPOSITION OF THE BULLET ITSELF. A NITRIC ACID SOLUTION HAS BEEN DISCOVERED WHICH WILL DISSOLVE COPPER. TO ESTABLISH WHICH NITRIC ACID PROCEDURE WOULD RAPIDLY REMOVE THE COPPER JACKET WITHOUT DESTROYING OR CHANGING THE BULLET, DIFFERENT CONCENTRATIONS OF THE ACID WERE TESTED. A 16M SOLUTION AT ROOM TEMPERATURE WAS FOUND TO DISSOLVE ALL JACKET MATERIAL IN 5 MINUTES WITHOUT HARMING THE BULLET OR PRODUCING A MAJOR CHANGE IN ITS ANTIMONY, SILVER, OR COPPER CONCENTRATIONS. THE EFFICACY OF THIS PROCESS WAS FURTHER TESTED BY COMPARING THE WEIGHTS OF EMPTY JACKETS, BULLETS FOR WHICH JACKETS HAD BEEN DISSOLVED, AND JACKETED BULLETS. THE 16M ROOM-TEMPERATURE CONCENTRATION DID NOT CHANGE THE BULLET LEAD WHERE ACID AND LEAD MEET. REMOVAL OF JACKET MATERIAL BEFORE BULLET ANALYSIS IS IMPORTANT TO PERMIT MEASUREMENT OF THE COPPER CONCENTRATION WITHIN THE BULLET AND TO AVOID BULLET ANALYSIS PROBLEMS CAUSED BY ADHERING PARTICLES OF COPPER. REFERENCES, TABLES, AND FOOTNOTES ARE INCLUDED. (PAP)