The Fourth Amendment prohibits the arrest of criminal suspects without probable cause to believe they have committed a crime. Yet after 9/11, former Attorney General John Ashcroft and the U.S. Department of Justice implemented a policy of misusing the federal “material witness” statute to detain Muslim men for investigative purposes without probable cause to believe that they’d committed any crime. Pursuant to this policy, our client, Abdullah al-Kidd, a Kansas-born U.S. citizen and former football player at the University of Idaho, was arrested on a material witness warrant in 2003 and imprisoned without charges for 16 days, ostensibly because the government wanted his testimony in someone else’s criminal case. He was never called to testify and never criminally charged.

Whether the government may require Caltech employees working under contract at the Jet Propulsion Laboratory in "low-risk" and "non-sensitive" jobs to disclose, among other things, information about medical treatment and psychological counseling that they may have received in connection with illegal drug use.

Whether this sex discrimination case against Wal-Mart should be allowed to proceed as a class action.

Whether a child's age may be considered as part of the totality of circumstances in determining whether a suspect is in custody and must therefore be given Miranda warnings prior to any police interrogation.