Justices Uphold Key Part of Arizona Law

Immigration Checks Allowed; Some Provisions Blocked

By JOHN H. CUSHMAN Jr. and ADAM LIPTAK

The Supreme Court on Monday rejected much of Arizona's immigration law but permitted the state's instruction to its police to check the immigration status of people they detain. In declining to take another look at its 2010 ruling, the court reversed a Montana Supreme Court decision that refused to follow i