IN ADDITION TO LISTNG ACCIDENTAL AND NONACCIDENTAL FIRE CAUSES, THIS GUIDE SUGGESTS WAYS FIRE FIGHTERS CAN AID IN ARSON INVESTIGATIONS, FROM THE MOMENT THEY ARRIVE ON THE SCENE, THROUGH THE POSTFIRE CLEANUP. FIREFIGHTERS ARE URGED TO LOOK FOR SUSPICIOUS FACES IN THE CROWDS THAT GATHER AROUND FIRES, TO STUDY THE COLOR OF THE FLAMES AT DIFFERENT STAGES OF THE FIRE, AND TO NOTE ANY SIGNS OF FORCED ENTRY OR WHETHER THE INVOLVED STRUCTURE IS SECURED AT THE DOORS AND WINDOWS. TIPS ARE PROVIDED ON DETERMINING HOW AND WHERE THE FIRE STARTED BY STUDYING CHARRING PATTERNS, ELIMINATING ACCIDENTIAL CAUSES, AND IDENTIFYING FIRESETTING MECHANISMS. EVIDENCE NECESSARY FOR CATCHING AND CONVICTING THE ARSONIST IS ALSO STRESSED, WITH ATTENTION TO RATIONAL AND IRRATIONAL MOTIVES, SIGNS OF BURNING FOR PROFIT, AND THE ROLE OF DIRECT AND CIRCUMSTANTIAL EVIDENCE. SUGGESTIONS ON HOW AND WHERE TO GET ADDITIONAL TRAINING ARE ALSO PROVIDED. DRAWINGS ARE INCLUDED. (KBL)