In the United States, the National Institute of Justice (NIJ) is the research, development and evaluation agency of the United States Department of Justice.
It has pages on its research after 9-11 into terrorism. Documents cover risk assessment, protective equipment, forensics, technology and social science. For instance as for high-risk targets, the NIJ funded a study that found that although bombings are the most prevalent terrorist threat to rail systems, most bombings produce few fatalities or injuries. The study also indentified 17 options for improving security, some of which are relatively inexpensive. Visit the NIJ website –