The purpose of the Expedited Removal of Criminal Aliens Act is to streamline the process for removing certain non-citizens from the United States who are involved in criminal activities. This legislation aims to enhance national security and public safety by quickly deporting individuals who are members of criminal gangs, affiliated with foreign terrorist organizations, or have been convicted of serious crimes. Key provisions of the Act include the establishment of a process for the expedited removal of non-citizens who meet specific criteria.