A blog can be a great place to dip into a new topic. Take the Snitching Blog, for example--an excellent resource for news and information about criminal informants, how they operate, and how they affect the U.S. criminal justice system. The blog has entries about cases in which an informant played a critical role, a heads-up about a recent NPR series on a confidential informant and the House of Death murders, and legislative reform efforts. You can find links to reports, data, and government hearings in the blog's sidebar.
Alexandra Natapoff, a professor at Loyola Law School, authors the blog. She recently published a book entitled Snitching: Criminal Informants and the Erosion of American Justice, Cornell Law Library call number KF9665 .N38x 2009. You also may want to check out Ethan Brown's Snitch: Informants, Cooperators & the Corruption of Justice, Cornell's Olin Library call number HV8141 .B74 2007. Ancient history buffs should try Imperial Inquisitions: Prosecutors and Informants from Tiberius to Domitian by Steven H. Rutledge, Olin Library call number JC89 .R87x 2001.