Legal Barriers to Information Sharing: The Erection of a Wall between Intelligence and Law Enforcement Investigations [open pdf - 3MB]
"As the threat of terrorism from radical Islamic groups developed, the FBI had both law enforcement and intelligence responsibilities in response to the threat. And it had different tools to use depending on whether its investigation was designated as an intelligence matter or a criminal matter. For criminal matters it could apply for and use traditional criminal warrants. For intelligence matters it could apply to a special court, known as the Foreign Intelligence Surveillance Court (FISC), for warrants pursuant to the Foreign Intelligence Surveillance Act (FISA) of 1978. This law governs electronic surveillance and physical searches of foreign powers and their agents within the United States. This divergence in purposes for the respective types of investigations and concerns about using intelligence techniques to advance law enforcement interests led to information sharing barriers being erected between the investigations. This paper will describe the history and development of the various barriers and their impact on the 9/11 story."
NEFA Foundation: http://www.nefafoundation.org/