The situation that describes a violation of the due process clause under the Fourteenth Amendment is:
The police performed a search on Stanley's house for illegal substances even though they did not have a search warrant. When they found a trunk full of illegal substances, they arrested Stanley.
This scenario illustrates a clear violation of due process, as the police conducted a search without a warrant, which is a fundamental requirement for lawful searches under the Fourth Amendment, which is applicable to the states through the Fourteenth Amendment.