In the case of Agosto v. Immigration and Naturalization Service, 1977, the U.S Supreme Court ruled in favor of the Immigration and Naturalization Service (INS). The petitioner, Mr. Agosto, was a resident alien with a criminal record who sought to avoid deportation by claiming that he had effectively been admitted into the United States when he entered Puerto Rico from Cuba in 1952. However, under immigration law at that time, entry into Puerto Rico did not constitute an "entry" into the United States for immigration purposes unless it was followed by an actual physical entry onto mainland territory. Since Mr. Agosto's first physical presence on mainland U.S soil occurred after his crimes were committed - which would have made him ineligible for discretionary relief from deportation - his argument was rejected by both INS and ultimately upheld by Supreme Court justices.

In the dissenting opinion for Agosto v. Immigration and Naturalization Service, Justice Marshall argued that the majority's decision was inconsistent with previous Supreme Court rulings concerning deportation cases. He contended that a noncitizen should not be deported based on evidence obtained illegally by law enforcement officials. In this case, he believed that Mr. Agosto’s Fourth Amendment rights were violated when his home was searched without a warrant and incriminating evidence was found leading to his deportation order. Justice Marshall also criticized the majority for failing to consider whether or not there had been an egregious violation of Fourth Amendment rights in this instance which would have warranted suppression of the evidence under existing precedent set by prior court decisions.