The Justice Department increasingly has refused to prosecute FBI cases targeting suspected terrorists over the past five years, according to private researchers who reviewed department records. The report being released Monday by the Transactional Records Access Clearinghouse at Syracuse University raises questions about the quality of the FBI's investigations. Prosecutors declined to bring charges in 131 of 150, or 87 percent, of international terrorist case referrals from the FBI between October 2005 and June 2006. That number marks the peak of generally steady increases from the 2001 budget year, when prosecutors rejected 33 percent of such cases from the FBI. The data raise troubling questions about the bureau's investigation of criminal matters involving individuals the government has identified as international terrorists," the report said. It noted that prosecutions in traditional FBI investigations since 2001-including drug cases, white collar crimes and organized crimes-have decreased while the number of agents and other employees has risen. "So with more special agents, many more intelligence analysts, and many fewer prosecutions the question must be asked: What is the FBI doing?" the report said.