The Bush administration has been handed another defeat in its efforts to prosecute suspects accused of plotting terror attacks in the United States. A Miami jury has acquitted one of the seven Miami men accused of planning to blow up Chicago’s Sears Tower. A mistrial was declared for the other six defendants after the jury deadlocked. The case had appeared to rest entirely on one suspect’s conversation with an FBI informant posing as a representative of al-Qaeda. The FBI later described the alleged plot as “aspirational rather than operational.”