The Supreme Court has cast doubt on the constitutionality of the federal sentencing guidelines used for nearly two decades. Congress created the complex system to eliminate disparities and increase certainty in sentencing federal defendants. The system requires judges to apply detailed numerical guidelines to calculate individual sentences, often based on new information never presented to the jury. Federal judges and defense lawyers have long complained that the procedures are too rigid and the sentences too harsh. But several recent Supreme Court decisions in state cases have required that juries, not judges, decide factual issues needed to raise or lower a defendant's sentence. The justices are now considering whether the same rule applies to the federal guidelines. A decision to throw out the guidelines could prompt Congress to step in with even tougher sentencing policies. The justices are also considering the constitutionality of imposing the death penalty on 16- and 17-year-olds — a practice some argue is “cruel and unusual punishment” prohibited by the Eighth Amendment.