As he briefed reporters in Boston on Tuesday afternoon, FBI special agent Richard DesLauriers detailed some of the physical clues the authorities had found during their investigation into Monday's bomb attacks: "Pieces of black nylon, which could be from a backpack, fragments of BBs [ball bearings] and nails, possibly contained in a pressure cooker device."
The task of turning those clues into answers now falls to the FBI laboratory in Quantico, Virginia, the state-of-the-art facility that inspired the television series CSI: Crime Scene Investigation.
When the FBI founded its first crime lab in Washington in 1932, it had just one member of staff: a handwriting analysis expert named Charles Appel. Two years later, Appel identified the Lindbergh baby's kidnapper and killer by matching his writing to the ransom notes. The lab went on to play a crucial role in all of the Bureau's biggest cases, including the JFK assassination in 1963, the Lockerbie bombing in 1988 and the 9/11 attacks in 2001.
Now, about 500 experts work at the lab, as well as travelling the globe. According to its website: "The men and women of the FBI Laboratory are dedicated to using the rigors of science to protect and defend the nation."
Much of the evidence to be examined in this case is shrapnel extracted from the victims. Donald Stern, a former US attorney, told Boston radio station WBUR: "Some of these cases get solved with a stray wire or a stray piece of metal or a label on a timing device. It's sometimes the smallest piece of evidence that is a pointer and leads to clues which then can lead back to the perpetrator."