To construct a psychological profile of the terrorist, investigators have tried to figure out his motives and how he thinks. In particular, they have studied his choice of targets and bomb-making style, which has always been quirky and meticulous. The Unabomber's devices are generally handcrafted, with many parts, including tiny levers, carved from wood. fbi forensics experts have found everything from scrap wood to pieces of mahogany and other hardwoods used in furniture. One bomb contained a twig from a cherry tree. The bomber makes some of his own metal parts too, including pins and even screws. Then the whole thing is generally placed in a homemade wooden box before being mailed or delivered.
His feelings about computers may have led the Unabomber to adopt the initials FC-they could stand for “f——— computers,” say investigators-which he has etched into parts of most of his bombs and which were scrawled on Sacramento State University buildings just before the 1993 attacks.