Law Enforcement Thinks The Boston Bombs Were Constructed From Pressure Cookers

According to NBC News, law enforcement is now saying that the bombs used in the attack on the Boston Marathon were constructed of pressure cookers filled with shrapnel. This is a common and low-rent bomb, typically made from a bit of TNT or other explosive in a sealed pressure cooker. They can be triggered remotely, and the pressure cooker itself turns into shrapnel. Time has a good history of the pressure cooker bomb, if you're interested. Pressure cookers make ideal bombs; they're inexpensive ...