NCJ Number
65113
Journal
Journal of Forensic Sciences Volume: 25 Issue: 1 Dated: (JANUARY 1980) Pages: 189-239
Date Published
1980
Length
51 pages
Annotation
INFRARED SPECTROSCOPY WAS USED TO DETERMINE THE CHEMICAL COMPOSITION OF 254 SAMPLES OF AUTOMOBILE REFINISHING TOPCOAT PAINT PRODUCTS AND TO ESTABLISH A DATA BASE FOR COMPARISONS OF SPECTRA OF UNKNOWN SAMPLES.
Abstract
FROM THE SPECTROSCOPY ANALYSIS OF THE SAMPLES, THE RESULTING INFRARED SPECTRA WERE SORTED INTO SPECIFIC PRODUCT LINES, AND THE CORRESPONDING SPECTRA WERE COMPARED WITH ONE ANOTHER. BECAUSE A SINGLE COLOR OF KNOWN PIGMENTATION COULD NOT BE COLLECTED, PIGMENT INTERFERENCES WITHIN THE SPECTRA WERE MINIMIZED BY CHOOSING THE INFRARED SPECTRA THAT BEST DISPLAYED THE RESIN SYSTEM FOR THE PRODUCT LINE. THE INFRARED SPECTRA ILLUSTRATED IN THE REPORT CAN BE EMPLOYED AS A DATA BASE TO WHICH AN UNKNOWN SPECTRUM CAN BE COMPARED TO IDENTIFY A SPECIFIC REPAINT TOPCOAT PRODUCT LINE. THE SPECTRA ARE ARRANGED ACCORDING TO THE MANUFACTURER'S DESIGNATIONS OF HIS OWN PRODUCTS AND TO WHETHER THE PAINT IS A NORTH AMERICAN OR IMPORTED PRODUCT. FROM SURVEY RESULTS, THE IDENTIFICATION AND APPREHENSION OF A HIT-AND-RUN REPAINTED MOTOR VEHICLE IS A POSSIBILITY. IN THE MAJORITY (80 TO 90 PERCENT) OF CASES, THE VEHICLES HAVE BEEN REPAIRED ON A SPECIFIC AREA, AND THE REPAIR SHOP HAS TRIED TO MATCH AS CLOSELY AS POSSIBLE THE ORIGINAL COLOR OF THAT VEHICLE. THE FORENSIC SCIENTIST CAN SUPPLY INVESTIGATORS WITH SOME INFORMATION THAT MAY, WITHIN CERTAIN LIMITS, AID THEM IN THEIR INVESTIGATIONS; FOR EXAMPLE, IF THE PHYSICAL APPEARANCES AND CHEMICAL COMPOSITION OF THE TOPCOAT MATCH A TYPE USED ON A SPECIFIC EUROPEAN OR BRITISH IMPORTED VEHICLE AS A FACTORY-PACKAGED REPAINT, THE INVESTIGATOR CAN BE REASONABLY CONFIDENT THAT SUCH A VEHICLE WAS INVOLVED IN THE INCIDENT. EXTENSIVE SPECTRA ILLUSTRATIONS AND REFERENCES ARE PROVIDED. (RCB)