NCJ Number
64892
Journal
Archiv fuer kriminologie Volume: 164 Issue: 3 & 4 Dated: (SEPTEMBER/OCTOBER 1979) Pages: 107-121
Date Published
1979
Length
15 pages
Annotation
POSSIBILITIES FOR DETERMING THE CALIBER, TYPE, AND VELOCITY OF BULLETS ON THE BASIS OF BULLET HOLES IN HUMAN SKULLS AND OTHER MATERIALS ARE EXPLORED.
Abstract
LITERATURE SHOWS THAT LITTLE CAN BE ASCERTAINED ABOUT CALIBER BY MEASURING THE SMALLEST DIAMETER ON THE SIDE WHERE THE BULLET ENTERED, BUT MEASURING BOTH SIDES OF THE FUNNEL SHAPED ENTRY AND EXIT HOLES PROVES MORE ACCURATE. TESTS ARE CONDUCTED ON GLASS PLATES AND ASBESTOS CEMENT PLATES, AND BULLET HOLES IN SKULLS FROM FORENSIC MEDICINE COLLECTIONS ARE EXAMINED. RESULTS INDICATE THAT THE SHAPE OF BULLET HOLES IS INFLUENCED BY THE ENERGY AND DEFORMATION TENDENCIES OF THE BULLET, AS WELL AS BY THE HARDNESS AND THICKNESS OF THE MATERIAL FIRED UPON. THUS, THE SIZE OF THE BULLET HOLE INCREASES WITH GREATER BULLET DEFORMATION TENDENCIES, WITH GREATER HARDNESS AND THICKNESS OF THE TARGET MATERIAL, AND WITH REDUCED BULLET VELOCITY. BECAUSE OF THE UNEVENNESS OF THE HUMAN SKULL, FINDINGS FROM TECHNICAL MATERIALS ARE DIFFICULT TO TRANSPOSE. DETERMINATION OF SKULL THICKNESS, SURFACE HARDNESS, AND AMOUNT OF HARD MATERIAL IS NOT ADEQUATE TO CHARACTERIZE SKULL RESISTANCE BECAUSE THE EFFECT OF SEPARATE LAYERS MUST ALSO BE CONSIDERED. A COMPACT SKULL WILL DEFORM A SHOT MORE THAN A SKULL WITH 'LAYERED' AMOUNTS OF HARD MATERIAL. WHILE HARD SHELL AMMUNITION ALMOST ALWAYS PENETRATES BOTH SIDES OF THE SKULL, LEAD BULLETS FREQUENTY DO NOT. CERTAIN CONCLUSIONS CAN BE REACHED ABOUT THE BULLET MATERIALS FROM METAL TRACES LEFT IN THE BULLET HOLE: LEAD TRACES CAN BE EASILY DETECTED WITH A SCANNING ELECTRON MICROSCOPE. SURFACE LEAD POWDER TRACES CAN BE PICKED UP BY X-RAYS. BULLET VELOCITY CAN ONLY BE APPROXIMATED IN CERTAIN CASES: A LARGE QUOTIENT BETWEEN THE OUTSIDE AND INSIDE MEASUREMENTS OF THE BULLET ENTRY HOLE SUGGESTS SLOW SHOT VELOCITY. ILLUSTRATIONS, TABLES, AND A BIBLIOGRAPHY ARE SUPPLIED. --IN GERMAN. (KMD)