Facts of the Case

A California court sentenced Mark James Knights to probation for a drug offense. The probation order included the following condition: that Knights would "submit his...person, property, place of residence, vehicle, personal effects, to search at anytime, with or without a search warrant, warrant of arrest or reasonable cause by any probation officer or law enforcement officer." In the aftermath of arson at the site of a Pacific Gas and Electric (PGE) power transformer, a sheriff's detective, with reasonable suspicion, searched Knights's apartment. Based in part on items recovered, including a PGE padlock, a federal grand jury indicted Knights for conspiracy to commit arson, for possession of an unregistered destructive device, and for being a felon in possession of ammunition. In granting Knights's motion to suppress, the District Court held that, although the detective had reasonable suspicion to believe that Knights was involved with incendiary materials, the search was for "investigatory" rather than "probationary" purposes. The Court of Appeals affirmed.

Question

Does a search pursuant to a common California probation condition, supported by reasonable suspicion, satisfy the Fourth Amendment?

Conclusion

Yes. In a unanimous opinion delivered by Chief Justice William H. Rehnquist, the Court held that the warrantless search of Knights, which was supported by reasonable suspicion and authorized by a condition of probation, was reasonable within the meaning of the Fourth Amendment. Noting that nothing in Knight's probation condition limits searches to those with a "probationary" purpose, the Court examined whether the Fourth Amendment imposed such a limitation. The Court then concluded that, based on ordinary Fourth Amendment analysis, reasonable suspicion is constitutionally sufficient to render a warrant requirement unnecessary. Justice David H. Souter filed a concurring opinion.