BOTH NEUTRON ACTIVATION ANALYSIS (NAA) AND ATOMIC ABSORPTION SPECTROSCOPY (AAS) SUFFER FROM PROBLEMS WHICH LIMIT THEIR UTILITY. THE TWO TECHNIQUES FALL INTO THE CATEGORY OF BULK ELEMENTAL ANALYSIS, WHICH IS LIMITED BY INABILITY TO DISTINGUISH BETWEEN DIFFERENT SOURCES FOR THE ELEMENTS FOUND OR TO DETERMINE WHETHER THE ELEMENTS ARE DISTRIBUTED OVER THE SURFACE SAMPLED IN DISCRETE PARTICLES OR AS A COATING. THIS CHARACTERISTIC COULD BE MISLEADING, SINCE SOME OF THESE ELEMENTS (E.G. BARIUM, LEAD) ARE COMMON ENVIRONMENTAL CONTAMINANTS. IN ADDITION, BOTH NAA AND AAS HAVE DIFFICULTIES IN LOCATING LEAD. THE SCANNING ELECTRON MICROSCOPE FOCUSES A THIN BEAM OF ELECTRONS ONTO THE SUBSTANCE TO BE EXAMINED AND SWEEPS IT ACROSS THE SUBSTANCE. AS THE ELECTRONS PASS OVER THE SUBSTANCE THEY KNOCK LOOSE ELECTRONS WHICH ARE PART OF THE ATOMS MAKING UP THE SUBSTANCE. A PERFECT VISUAL REPLICA OF THE SURFACE OF THE OBJECT BEING SCANNED IS PRODUCED. SEM IS CAPABLE OF DISTINGUISHING BETWEEN DISCRETE PARTICLES AND COATINGS. A 4-YEAR STUDY CONDUCTED BY THE AEROSPACE CORPORATION (EL SEGUNDO, CALIF.) FOR LEAA, HAS CONCLUDED THAT USING SEM FOR ANALYSIS WAS THE METHOD GIVING GUNSHOT RESIDUE THE MOST POSITIVE IDENTIFICATION AND THE METHOD WITH THE HIGHEST SUCCESS RATE IN ACTUAL CASES. FURTHERMORE, SEM ANALYSIS HAS BEEN RECENTLY APPROVED IN A CALIFORNIA APPELLATE COURT. AN ADDITIONAL BENEFIT OF SEM IS THAT IT IS NOT RESTRICTED TO DETECTION OF GUNSHOT RESIDUE, BUT HAS ALREADY PROVED CAPABLE OF IDENTIFYING BITE-MARKS IN SUBSTANCES AS PLIABLE AS HUMAN SKIN. NO DATA OR REFERENCES ARE PROVIDED. DIAGRAMS ILLUSTRATE THE REPORT. (AUTHOR ABSTRACT MODIFIED--MLC)