Trupiano v. United States

Background

In 1946 four men sought to rent part of a New Jersey farm and built a barnlike structure to operate an illegal distillery. A farm owner informed federal Alcohol Tax Unit agents, who placed an undercover agent on the farm and monitored operations for weeks. On June 3 agents entered with the owner, arrested one man in the building, and seized the still, vats, and 262 five‑gallon cans of alcohol without securing a search warrant. Lower courts denied a motion to suppress the seized property.

Reasoning

The Court addressed whether agents could seize known contraband during a planned raid without a search warrant simply because one person was arrested on the premises. The majority held that although the on‑scene arrest was lawful, the seizure violated the Fourth Amendment because agents had ample time to get a warrant and the need for a summary seizure was not shown. The Court therefore reversed the denial of the suppression motion and excluded the evidence.

Real world impact

The decision limits when police and federal agents can grab evidence without judicial approval. Prosecutors cannot rely on warrantless seizures made during planned, surveilled operations, and defense lawyers can seek suppression of such evidence. The Court did note that contraband need not be returned, but it barred use of improperly seized items at trial.

Dissents or concurrances

A four‑justice dissent argued the seizure was lawful as an incident to a valid arrest and in plain view, warning the ruling would hamper effective law enforcement.