WASHINGTON, July 20 A report by internal investigators at the Justice Department has identified dozens of recent cases in which department employees have been accused of serious civil rights and civil liberties violations involving enforcement of the sweeping federal antiterrorism law known as the USA Patriot Act. The inspector general's report, which was presented to Congress last week and is awaiting public release, is likely to raise new concern among lawmakers about whether the Justice Department can police itself when its employees are accused of violating the rights of Muslim and Arab immigrants and others swept up in terrorism investigations...