A Department of Homeland Security Center of Excellence led by the University of Maryland

Measuring Intervention Success in Terrorist Activities


Measuring Intervention Success in Terrorist Activities

Investigators: 

Project Details

Abstract: 

The goal of this project was to determine whether federal efforts to intervene in terrorism activities could be empirically measured. We assumed that as a result of publicly announced changes in federal efforts to become more proactive in responding to terrorism would have significant changes in the manner and success of prosecutorial efforts.This project considered the following measurements with regards to intervention success in terrorist activities:  (1) the ratio of persons indicted to persons convicted; (2) measures of crime severity relative to charging decisions and case outcomes; (3) the ratio of number of charges per person or indictment to number of charges in which a conviction was obtained; and (4) changes over time in the ratio of the number of "prevented" acts of terrorism to the number of "completed" acts of terrorism in the United States.

Primary Findings: 

Efforts to prevent terrorism have significant ramifications for federal prosecutors. Early intervention may force prosecutors to issue indictments before the full scope of a conspiracy is known, before confidential informants can be embedded in a terror cell, and before important pre-cursor criminal conduct occurs. This research examined the impact of "proactive policing" on prosecutorial conduct and conviction success.

  • Evidence of a move to proactive policing is reflected in a change in the proportion of indictments involving prevented versus completed acts of terrorism. Prior to the September 11 attacks, only 29% of all indictments involved prevented acts; in the three years after the attacks, this proportion increased to 60%.
  • Indicative of a move to early interdiction, terrorists indicted after 9/11 were charged with fewer counts per persons, a reduction of 13.8 counts per person to 7.9 counts per person.
  • Similarly, in an effort to intervene earlier, prosecutors indicted fewer defendants per case after 9/11, dropping from 3.7 defendants per indictment to 1.6 defendants per case.
  • Early intervention also restricts the ability to use confidential informants. 73% of pre 9/11 cases involved CI's, compared to 20% in post 9/11 cases. Similarly, 37% of pre-9/11 cases involved evidence provided by an undercover government agent, compared to 4% of post-9/11 cases. Prosecutors in post 9/11 cases were probably indicting with less evidence than in the pre 9/11 era.
  • Probably as a result of the above, prosecutors won convictions on a much smaller proportion of charges filed in the post 9/11 era than in the pre 9/11 era (18% compared to 62%, respectively).
  • There was no change in the severity of the lead offense filed before and after 9/11.
  • Plea bargaining rates changed dramatically after 9/11, increasing from 49% among 1983-2001 terrorists to 85% among post-9/11 indictees.
  • Despite these changes, the overall conviction rate for terrorists indicted in the three years after the 9/11 attacks did not change. Both pre- and post 9/11 terrorists had a 71% conviction rate.
Methodology: 

The goal of this project was to determine whether federal efforts to intervene in terrorism activities could be empirically measured. We assumed that as a result of publicly announced changes in federal efforts to become more proactive in responding to terrorism would have significant changes in the manner and success of prosecutorial efforts. To accomplish this evaluation, we used federal terrorism cases from the American Terrorism Study (ATS) database for the period 1983-2004. Cases were sorted based on two criteria. First, cases with indictment dates prior to September 11, 2001 were categorized as pre-9/11, while cases with indictment dates after September 11, 2001 were categorized as post-9/11. Second, cases were labeled as either "preventions" or "completions" based on an analysis of the categorization identified in the Federal Bureau of Investigation's annual reports entitled Terrorism in the United States for the year's 1983-2004. Discrepancies between court case documents and the FBI reports were handled on an individual basis. Dependent variables included: conviction rate; average number of counts per indictment; percentage of cases resulting in plea agreements; count severity; number of defendants per case; and percentage of nonconvicted counts per case. Preliminary analyses were performed using descriptive statistics and independent samples t-tests.

Timeframe

Project Period: 
September 2008 to June 2010