THE TEXT BEGINS WITH A REVIEW OF SEVERAL FAMOUS CASES OF ARSON FROM HISTORY, INCLUDING THE REICHSTAG FIRE DURING HITLER'S REGIME IN GERMANY AND THE 1976 FIRE IN A NEW YORK CITY PUERTO RICAN SOCIAL CLUB WHICH RESULTED IN THE DEATH OF 25 PEOPLE. THE MAJOR MOTIVES FOR ARSON ARE OUTLINED: FINANCIAL GAIN (PROBABLY BEHIND 40 PERCENT OF DELIBERATELY SET FIRES); INDIRECT FINANCIAL GAIN (A THIRD PARTY, RATHER THAN THE STRUCTURE'S OWNER, PROFITS FROM THE DESTRUCTION BY ELIMINATING A COMPETITOR'S BUSINESS, OBTAINING A CONTRACT TO BUILD A NEW STRUCTURE, OR SELLING A NEW INSURANCE POLICY); REVENGE FOR A QUARREL; INTIMIDATION (THREATENING ARSON TO FRIGHTEN OTHERS INTO AN AGREEMENT); CONCEALMENT OF ANOTHER CRIME; FOR FUN; AND A PSYCHOLOGICAL NEED TO SET FIRES (PYROMANIA). ARSON RINGS, A GROUP OF TWO OR MORE PERSONS ENGAGED IN ARSON FOR PROFIT, ARE LOOSELY CONNECTED GROUPS THAT SET FIRES FOR CLIENTS WHO ARE USUALLY PERSONALLY UNKNOWN TO THEM. PYROMANIACS ARE PERSONS WHOSE NEED TO SET FIRES USUALLY IS CORRELATED WITH DRUG OR ALCOHOL USE, AND UNHAPPY HOME LIFE, UNEMPLOYMENT, OR AN UNSATISFACTORY SEX LIFE. THEY USUALLY STAY TO WATCH THEIR FIRES AND ARE OFTEN IDENTIFIED IN FIRE SCENE PHOTOGRAPHS. TEENAGE FIRE SETTERS BURN TO RELIEVE BOREDOM AND HAVE FUN. THE TYPICAL TOOLS OF ARSONISTS ARE DEVISED MECHANISMS SUCH AS CANDLES SET IN COMBUSTIBLE MATERIALS, CHEMICALS SUCH AS WHITE PHOSPHORUS AND THERMITE, AND VARIOUS TYPES OF EXPLOSIVES SUCH AS MERCURY FULMINATE, NITROGLYCERIN, AND GUNPOWDER. TO DETECT THE SOURCE OF THE FIRE, FIREFIGHTERS SHOULD BE ALERT TO THE SMELL AND COLOR OF THE FLAME AND SMOKE, DRAWN SHADES OR COVERED WINDOWS, AND EVIDENCE SUCH AS EQUIPMENT LEFT AT THE SCENE. ALL STAGES OF THE FIRE AND THE SPECTATORS AT THE SCENE SHOULD BE PHOTOGRAPHED. INVESTIGATORS PROBING FIRE DEBRIS SHOULD DETERMINE WHERE THE FIRE STARTED, CHECK FIRE PROTECTION SYSTEMS, AND PAY PARTICULAR ATTENTION TO CHARRED AREAS. AN INDEX AND PHOTOGRAPHS ARE PROVIDED. (DAG)