## Facts

- An NYPD officer observed Nelson Sibron over several hours speaking with multiple people the officer knew to be narcotics addicts, but the officer did not overhear conversations or see anything exchanged.
- The officer later approached Sibron outside a restaurant, stated “You know what I am after,” and when Sibron moved toward his pocket, the officer reached directly into Sibron’s pocket and removed envelopes containing heroin.
- Sibron was charged with unlawful possession of heroin and moved to suppress the heroin as the product of an unconstitutional search.
- The trial court denied suppression on a probable-cause rationale; Sibron pleaded guilty while preserving appellate review of the suppression ruling, and New York appellate courts affirmed.
- While Sibron’s appeal was pending, he completed his sentence.
- The Supreme Court considered Sibron’s case together with Peters v. New York, involving a separate street encounter and frisk leading to the seizure of burglar’s tools.

## Issues

1. Whether Sibron’s appeal was moot because he completed his sentence before appellate review.
2. Whether the officer’s warrantless search of Sibron’s pocket and seizure of heroin was reasonable under the Fourth Amendment as (a) a search incident to a lawful arrest or (b) a limited protective frisk for weapons.
3. Whether the Court should assess the validity of New York’s stop-and-frisk statute in the abstract or decide only the constitutionality of the particular search and seizure.

## Decision

- The Supreme Court held Sibron’s case was not moot because criminal convictions carry potential collateral legal consequences beyond completion of a sentence.
- The Court declined to issue a broad facial ruling on the stop-and-frisk statute and instead evaluated the reasonableness of the specific police conduct.
- The Court reversed Sibron’s conviction, holding the heroin should have been suppressed under the Fourth Amendment.
- The Court found no probable cause to arrest Sibron based solely on his observed conversations with known addicts, where the officer saw no exchanges and heard no incriminating statements.
- The Court held the search could not be justified as incident to arrest because a search may not precede an arrest and then supply the justification for the arrest.
- The Court held the search was not a valid protective frisk because the officer lacked specific facts suggesting Sibron was armed and dangerous and because the officer bypassed a limited pat-down and reached directly into Sibron’s pocket.

## Legal Principles

- A criminal appeal is not rendered moot by completion of a sentence when collateral legal consequences may flow from the conviction.
- Fourth Amendment review of stop-and-frisk practices focuses on whether the particular search and seizure was reasonable under the circumstances.
- Probable cause to arrest cannot rest on a generalized inference that speaking with suspected or known criminals indicates criminal conduct.
- A search incident to arrest must follow and be supported by a lawful arrest; it cannot precede the arrest and serve as its justification.
- A protective frisk for weapons requires specific, articulable facts supporting a reasonable belief the person is armed and dangerous, and it is ordinarily limited to a pat-down of outer clothing, with further intrusion justified only by what the pat-down reveals.

## Conclusion

The Court held that Sibron’s conviction could not stand because the officer lacked probable cause and lacked a valid, limited self-protective basis to search, making the pocket search and seizure of heroin unreasonable under the Fourth Amendment and requiring suppression of the evidence.


Sibron v. New York, 392 U.S. 40 (1968)