The LaRouche criminal trials in the mid-1980s stemmed from federal and state investigations into the activities of American political activist Lyndon LaRouche and members of his movement. They were charged with conspiring to commit fraud and soliciting loans they had no intention of repaying. LaRouche and his supporters disputed the charges, claiming the trials were politically motivated.
In 1986, hundreds of state and federal officers raided LaRouche offices in Virginia and Massachusetts. A federal grand jury in Boston, Massachusetts, indicted LaRouche and 12 associates on credit card fraud and obstruction of justice. The subsequent trial, described as an "extravaganza", was repeatedly delayed and ended in mistrial. Following the mistrial, a federal grand jury in Alexandria, Virginia, indicted LaRouche and six associates. After a short trial in 1988, LaRouche was convicted of mail fraud, conspiracy to commit mail fraud, and tax evasion, and was sentenced to prison for fifteen years. He entered prison in 1989 and was paroled five years later. At the same trial, his associates received lesser sentences for mail fraud and conspiracy. In separate state trials in Virginia and New York, 13 associates received terms ranging from one month to 77 years. The Virginia state trials were described as the highest-profile cases that the state Attorney General's office had ever prosecuted. Fourteen states issued injunctions against LaRouche-related organizations. Three LaRouche-related organizations were forced into bankruptcy after failing to pay contempt of court fines.
Defense lawyers filed numerous unsuccessful appeals that challenged the conduct of the grand jury, the contempt fines, the execution of the search warrants and various trial procedures. At least ten appeals were heard by the United States court of appeals, and three were appealed to the U.S. Supreme Court. Former U.S. Attorney General Ramsey Clark joined the defense team for two appeals. Following the convictions, the LaRouche movement mounted failed attempts at exoneration.