NCJ Number
218833
Journal
Forensic Science Communications Volume: 1 Issue: 2 Dated: July 1999 Pages: 1-28
Date Published
July 1999
Length
28 pages
Annotation
The Paint Subgroup of the FBI Laboratory's Scientific Working Group for Materials Analysis presents revised guidelines for forensic paint analysis and comparison.
Abstract
The guidelines are intended to assist personnel who conduct forensic paint analyses in the evaluation, selection, and application of tests that may be of value to the investigation. The guidelines describe methods for developing discriminatory information by using an efficient and reasonable order of testing. The need for validated methods and quality assurance guidelines is also addressed. A summary of practice focuses on physical and chemical features of paint films, questioned and known samples, motor vehicle identification, and sample documentation. Procedures for the collection of suitable samples are also included in the guidelines. Guidelines for procedures in forensic paint analysis cover a variety of potentially useful techniques for the discrimination of paint binders, pigments, and additives. A flowchart is provided as a guide for determining the possible origins of motor vehicle paint in a case. Guidelines for procedures also address sample description, physical match, and sample preparation and layer analysis. Guidelines are presented for performing the following methods of forensic analysis of paints: solvent/microchemical tests, polarized light microscopy, vibrational spectroscopy, pyrolysis gas chromatography, microspectrophotometry, scanning electron microscopy, X-ray fluorescence spectrometry, and X-ray diffraction. Other analytical techniques covered in the guidelines are fluorescence microscopy, low-temperature ashing, solvent extraction, analytical electron microscopy, and cathodoluminescence. 57 references