When police have specific and articulable facts from which they reasonably believe that there exists a great potential for deadly harm, they may conduct a limited search of a vehicle to ensure their safety.

The warrantless search of an automobile incident to an arrest is limited to the areas and clothing immediately accessible to the person arrested. The purpose of this search is to prevent the arrestee from securing weapons or destroying contraband. When a bag is outside the area of immediate control of the arrestee, it cannot be searched incident to arrest, or searched without a warrant simply because it was seized from an automobile.

Individualized reasonable suspicion is not necessary when the search of a student population affects a limited privacy interest, is minimally intrusive, is preceded by adequate notice, is motivated by a significant policy concern, and is directed towards an immediate need.

A policy requiring all students who participate in competitive extracurricular activities to submit to drug testing is a reasonable means of furthering the school district's important interest in preventing and deterring drug use among its schoolchildren, and therefore such a policy does not violate the Fourth Amendment.

"The accommodation of the privacy interests of schoolchildren with the substantial need of teachers and administrators for freedom to maintain order in the schools does not require strict adherence to the requirement that searches be based on probable cause to believe that the subject of the search has violated or is violating the law. Rather, the legality of a search of a student should depend simply on the reasonableness, under all the circumstances, of the search. . . . [F]irst one must consider whether the . . . action was justified at its inception; second, one must determine whether the search as actually conducted was reasonably related in scope to the circumstances which justified the interference in the first place. Under ordinary circumstances, a search of a student by a teacher or other school official will be 'justified at its inception' when there are reasonable grounds for suspecting that the search will turn up evidence that the student has violated or is violating either the law or the rules of the school. Such a search will be permissible in its scope when the measures adopted are reasonably related to the objectives of the search and not excessively intrusive in light of the age and sex of the student and the nature of the infraction."

Individualized searches of public school students conducted by school officials, including school police officers, are subject to a reasonable suspicion standard under the Pennsylvania Constitution.

School officials do not act as agents of the police when they conduct an independent investigation based upon information the officials received from police. School officials do not need reasonable suspicion, supported by specific and articulable facts, before merely detaining and questioning a student about a rumor concerning his or her possession of a gun on school property. Also, school officials need not provide Miranda warnings to a student before questioning the student about conduct that violates the law and/or school rules. However, this rule only is limited to situations where school officials do not act at the behest of law enforcement officers.

Standardized criteria or established routine must govern the conduct of an inventory search. On the question, for example, of whether a container should be opened during an inventory search, it would be constitutional for there to be a policy that all containers should be opened, and equally valid for the policy to be that no containers should be opened. The search procedures may also allow the officer some discretion, for example, a policy that requires the opening of containers whose contents cannot be determined without opening. However, if a police officer is allowed too much latitude in conducting a search, it raises the danger that inventory searches will be used as a general investigative tool. Where no policy exists at all regulating inventory searches, the Fourth Amendment is violated.

In determining whether a proper inventory search has occurred, the first inquiry is whether the police have lawfully impounded the automobile, i.e., have lawful custody of the automobile. The authority of police to impound vehicles, for purposes of an inventory search, derives from their reasonable community caretaking functions, and such functions include removing disabled or damaged vehicles from the highway, impounding automobiles which violate parking ordinances, thereby jeopardizing public safety and efficient traffic flow, and protecting the community's safety. While a vehicle may be exposed to danger if it is left legally parked on a public street in a high-crime area, this concern, standing alone, is inadequate to override the defendant's reasonable expectations of privacy. The second inquiry is whether the police have conducted a reasonable inventory search. An inventory search is reasonable if it is conducted pursuant to reasonable standard police procedures in good faith and not for the sole purpose of investigation.