Coolidge v. New Hampshire
The Supreme Court threw out key evidence used to convict a New Hampshire man of murdering a 14-year-old babysitter, ruling that the search warrant for his car was invalid because it had been issued by the state's own top prosecutor rather than a neutral judge.
The Court also rejected the state's backup arguments — that the car search fit exceptions for arrests, moving vehicles, or evidence in plain view — tightening the rules for when police can search and seize a car without first getting a warrant from an independent magistrate.
“The word "automobile" is not a talisman in whose presence the Fourth Amendment fades away and disappears.”
The majority's rejection of a blanket automobile exception to the warrant requirement.
How it got here: A New Hampshire trial judge sent pretrial suppression motions to the state supreme court, which found the evidence admissible; Coolidge was convicted, the state supreme court affirmed, and the U.S. Supreme Court agreed to review the case.
The Case in Depth
What happened
A 14-year-old babysitter, Pamela Mason, disappeared from her Manchester, New Hampshire home in 1964 and was later found murdered. Police suspected Edward Coolidge, a man who had been away from home that night. Coolidge's wife voluntarily handed over guns and clothing to police, and weeks later the state's attorney general — who was directing the investigation and would later prosecute the case — personally signed a warrant to search Coolidge's car, which was towed and searched for evidence used at trial.
The question before the Court
Could New Hampshire's attorney general — who was personally leading the murder investigation and would later prosecute the case — issue a valid search warrant for the suspect's car, and could police instead just seize the car from his driveway without any warrant naming it?
Why it matters
The ruling meant Coolidge's murder conviction was overturned and a new trial ordered, years after the crime. More broadly, it barred prosecutors and police officials from doubling as the magistrates who approve their own warrants, and it made clear that police generally cannot seize a car they've already identified as evidence just because it's sitting in plain sight — they still need a warrant unless a true emergency exists.
What changes now
The case was sent back to the New Hampshire Supreme Court for further proceedings, meaning the evidence obtained from the car search could not be used again and the state would need to decide whether to retry Coolidge without it. This is a final decision on the merits of the Fourth Amendment questions presented, not a temporary order, though it left open the separate, harder question of whether police generally need a warrant to enter a home and arrest someone.
What this does not decide
The Court explicitly left open whether police always need an arrest warrant before entering a home to arrest someone on probable cause, calling that a "grave constitutional question" better left for a case that squarely presents it. The ruling is also limited to the specific facts here — a car police already knew about and planned to seize — not every roadside or public-place vehicle search.
Concurrences and dissents
Concurrence — Justice Harlan
Justice Harlan agreed with the outcome only because he felt bound by Mapp v. Ohio and Ker v. California, which he thought were wrongly decided and should be overruled. He argued state search-and-seizure law shouldn't be forced into a rigid federal mold, and he would have preferred to uphold the conviction if not for those precedents. He also stressed that the Court rightly avoided deciding whether warrantless home entries to arrest are always constitutional.
Dissent in part — Justice Black
Justice Black argued the Fourth Amendment itself contains no exclusionary rule — any exclusion of evidence should come from the Fifth Amendment's self-incrimination clause, not judge-made Fourth Amendment doctrine. He also believed the car seizure and search were reasonable under search-incident-to-arrest, automobile, and plain-view theories, and would have affirmed the conviction entirely.
Dissent in part — Justice White
“It is a metaphysical distinction without roots in the commonsense standard of reasonableness governing search and seizure cases.”White's objection to the majority's distinction between moving and merely movable vehicles.
Justice White argued the car was lawfully seized in plain sight while police were legitimately on the property to arrest Coolidge, and could then be searched under Cooper v. California. He criticized the majority's new 'inadvertence' requirement for plain-view seizures as arbitrary and unworkable, arguing it would create inconsistent results for evidence police fully expected to find versus evidence found by surprise.
Dissent in part — Justice Burger
Chief Justice Burger joined Justice White's dissent and much of Justice Black's opinion, agreeing the search was reasonable and objecting to what he called the exclusionary rule's 'monstrous price.' He argued the majority strained to create new rules and unnecessarily forced a retrial more than seven years after the crime, though he agreed with the majority on the wife's voluntary handover of evidence.
How the Court got there
The legal reasoning, step by step
- The Court applied the basic rule that a search warrant must be issued by a neutral and detached magistrate, not by the police or prosecutors themselves; because the New Hampshire attorney general was actively directing the murder investigation and would later serve as chief prosecutor, he could not act as that neutral decision-maker, so the warrant for the car was invalid.
- With no valid warrant, the Court treated the car seizure as if no warrant existed at all and asked whether any recognized exception to the warrant requirement covered it, since warrantless searches are presumed unreasonable unless a specific, narrow exception applies.
- The Court rejected the theory that the seizure was a valid 'search incident to arrest' — a doctrine allowing warrantless searches of the area within an arrestee's immediate reach — because under the law in effect at the time, that exception did not extend to a car parked outside while the arrest happened inside the house.
- The Court also rejected the 'automobile exception,' which lets police search a car without a warrant when it is mobile and could disappear before a warrant is obtained, because Coolidge's car was parked at his home, he was cooperative, and there was no urgency or risk the car would vanish.
- Turning to the 'plain view' doctrine — which allows warrantless seizure of evidence police stumble across unexpectedly — the Court held the doctrine did not apply because police already knew the car's exact location and had planned all along to seize it, so its discovery was not accidental or inadvertent.
- Because none of the three exceptions applied, the Court concluded the car seizure and later search violated the Fourth and Fourteenth Amendments, while separately holding that the wife's voluntary handover of guns and clothing was not a police-directed search at all and remained valid evidence.
Doctrinal impact
Cases affected by this decision
Distinguishes Carroll v. United States (267 U.S. 132)
The Court held Carroll's automobile exception did not apply because there was no urgency or risk the parked car would disappear.
Distinguishes Chambers v. Maroney (399 U.S. 42)
The Court found Chambers did not extend to seizing a parked, unoccupied car with no exigent circumstances.
Limits Trupiano v. United States (334 U.S. 699)
The Court relied on Trupiano's reasoning about anticipated evidence but declined to revive all of its broader implications.
Reaffirms Chimel v. California (395 U.S. 752)
The Court applied and relied on Chimel's narrow limits on searches incident to an arrest.