As a fellow at the University of California-Berkeley’s Investigative Reporting Program, Florida Center for Investigative Reporting Associate Director Trevor Aaronson spent a year researching how the FBI uses informants in terrorism investigations. Aaronson’s findings, which were published in the September/October issue of Mother Jones, include:

  • The FBI has 15,000 registered informants, many of them keeping watch on Muslim communities. Today, the FBI has nearly three times as many informants as it had 25 years ago.

Aaronson’s report also includes a searchable database of the more than 500 terrorism prosecutions reviewed during the yearlong investigation.

Listen to Aaronson discuss his investigation with NPR host Laura Sullivan on the Aug. 21 edition of All Things Considered: