Report: Law Enforcement, Public Vigilance Lead to 80 Percent of Foiled Terror Plots

More than 80 percent of foiled terrorist plots between 1999 and 2009 resulted from observations by citizens or law enforcement officials or from law enforcement investigations, according to a report recently published by the Institute for Homeland Security Solutions.

This report resulted from an ongoing study that reviewed open-source information on 86 foiled and successful terrorist plots against U.S. targets from 1999 to 2009.

The aim of the research was to determine and better understand the types of information and activities that foiled (or could have foiled) such attacks.

"Since 2001, the intelligence community has sought better ways to detect and prevent domestic terrorist plots, said Kevin J. Strom, senior research scientist and the report's lead author in a prepared statement. "What this report reveals is the vital role played by citizens as well as state and local U.S. law enforcement agencies in uncovering such planned attacks."

These tips included reports of specific plots as well as reports of suspicious activity, such as pre-operational surveillance, paramilitary training, smuggling activities, and the discovery of suspicious documents.

Among the report's other findings:

• plots by single actors ("lone wolves") have proven particularly successful, reaching execution nearly twice as often as plots by groups;
• more than one in five plots were uncovered during investigations into seemingly unrelated crimes such as robberies, arson or parole violations (which ld to the recommendation that training is needed to ensure that ordinary crimes possibly connected to terrorism are recognized and properly investigated);
• tips from the public or from informants or undercover officers helped law enforcement officials uncover 40 percent of the plots that were thwarted;
• less than half of all the U.S. terrorism plots examined were motivated by Islamic extremists;
• tactics such as racial, ethnic, religious, or ideological profiling may harm efforts to establish trust with persons in or near radical movements who could otherwise be helpful to law enforcement officials.

To access the complete report, please visit:

IHSS: Building on Clues: Examining Success and Failures in Detecting U.S.Terrorist Plots, 1999-2009