NCJ Number
1905
Date Published
1970
Length
144 pages
Annotation
EARLY WORK IN NEUTRON ACTIVATION ANALYSIS IS REVIEWED AND APPLIED TO THE ANALYSIS OF GUNSHOT RESIDUES IN SCIENTIFIC CRIME DETECTION.
Abstract
IN THE PRESENT INVESTIGATION, LARGE-SCALE STATISTICAL STUDIES WERE CONDUCTED OF GUNSHOT RESIDUES FROM REVOLVERS AND AUTOMATIC PISTOLS OF VARIOUS COMMON CALIBERS, AND OF BA AND SB PRESENT ON THE HANDS OF PERSONS, OF VARIOUS OCCUPATIONS, WHO HAD NOT RECENTLY FIRED A GUN (OCCUPATIONAL HANDBLANKS). THESE LARGE-SCALE STUDIES RESULT IN A LARGE BODY OF EXPERIMENTAL DATA - PRESENTED IN FULL IN THIS REPORT. CONCURRENTLY, A SUITABLE STATISTICAL METHOD FOR THE INTERPRETATION OF SUCH BA-SB DATA WAS DEVELOPED - THE BIVARIATE-NORMAL (BVN) METHOD ACTUALLY A BIVARIATE LOG-NORMAL TREATMENT. THE DEVELOPMENT OF THE BVN METHOD, ITS APPLICATION TO THE ACCUMULATED BA-SB DATA, AND ITS POTENTIAL USE IN THE INTERPRETATION OF ACTUAL CRIMINAL-CASE RESULTS ARE ALSO PRESENTED IN THIS REPORT. IT IS SHOWN THAT, IN MOST INSTANCES, BA-SB RESULTS - PROPERLY OBTAINED AND PROPERLY INTERPRETED - CAN PROVIDE A FAIRLY DEFINITIVE DISTINCTION BETWEEN A HAND THAT HAS RECENTLY FIRED A HANDGUN AND ONE THAT HAS NOT (OR ONE THAT HAS SUBSEQUENTLY BEEN WASHED BEFORE BEING SAMPLED). (AUTHOR ABSTRACT MODIFIED.)