THE RESEARCHERS DISCOVERED THAT, WITH THE EXCEPTION OF A CONTACT WOUND, THERE CAN BE NO MEANINGFUL APPROXIMATION OF MUZZLE-TO-BULLET-CONTACT DISTANCE WITHOUT FIRST CONDUCTING CONTROLLED FIRINGS UTILIZING THE SUSPECT'S WEAPONS AND AMMUNITION, OR AMMUNITION OF THE SAME MAKE AND LOT. FURTHERMORE, ANY APPROXIMATION OF DISTANCE BASED SOLELY UPON ENTRANCE HOLE DIAMETER AND POWDER PATTERN WITHOUT FIRST FIRING COMPARATIVE RESIDUE PATTERNS IS PATENTLY UNRELIABLE, BECAUSE OF THE UNLIMITED PATTERN CHANGES AVAILABLE THROUGH THE MANIPULATION OF POWDER TYPE, CHARGE, CHEMISTRY, AND BARREL LENGTHS IN THE SAME CALIBER. PHOTOGRAPHS ILLUSTRATE DIFFERENT TYPES OF PATTERNS. (AUTHOR ABSTRACT)