Whether the Fourth Amendment permits a warrantless search of a probationer's home, supported by reasonable suspicion and authorized by a probation search condition, when officers conduct the search for an ordinary law-enforcement purpose.
Holding
Yes. A warrantless search of a probationer subject to a clear search condition is reasonable when officers have reasonable suspicion of criminal activity, even if their purpose is investigatory rather than probationary.
Reasoning
The Court rejected the Ninth Circuit's distinction between probationary and investigatory searches. Knights's condition authorized searches by both probation officers and law-enforcement officers and imposed no purpose-based limitation. Its text therefore did not confine searches to supervision of probation compliance.
Griffin v. Wisconsin did not compel a different result. Griffin upheld a probation search under the special-needs rationale of probation supervision, but it expressly left open whether a warrantless probation search could also be reasonable under ordinary Fourth Amendment principles. An opinion sustaining one kind of search does not silently invalidate every different kind of search.
Under the ordinary totality-of-the-circumstances framework, the Court balanced the intrusion on Knights's privacy against the governmental interests served. Probation is a criminal sanction that necessarily restricts liberty, and a sentencing court may impose reasonable conditions designed to advance rehabilitation and protect the public. Because Knights received clear notice of, and agreed to, the search condition, his reasonable expectation of privacy was significantly diminished.
The government also has a strong interest in monitoring and investigating probationers. Probationers are more likely than ordinary citizens to reoffend, and they have incentives to conceal or quickly dispose of evidence because a violation can result in revocation and incarceration. The State need not ignore evidence that a probationer is committing new crimes merely because the investigation also serves ordinary law-enforcement goals.
This balance made reasonable suspicion, rather than probable cause, sufficient. Reasonable suspicion that a probationer subject to a search condition is engaged in criminal activity provides enough likelihood of wrongdoing to justify the intrusion on the probationer's reduced privacy interest. The same circumstances also made a warrant unnecessary. Because Knights conceded, and the District Court found, that Detective Hancock had reasonable suspicion, the search was constitutional.