When exigent circumstances are not the result of illegal activity by the police but flow from a proper Terry stop that unavoidably creates the exigency, the police may execute a search without a warrant.

"In determining whether exigent circumstances exist, a number of factors are to be considered. Among the factors to be considered are: (1) the gravity of the offense, (2) whether the suspect is reasonably believed to be armed, (3) whether there is above and beyond a clear showing of probable cause, (4) whether there is a strong reason to believe that the suspect is within the premises to be searched, (5) whether there is a likelihood that the suspect will escape if not swiftly apprehended, (6) whether the entry was peaceable, and (7) the time of the entry, i.e., whether it was made at night. These factors are to be balanced against one another in determining whether the warrantless intrusion was justified. Other factors may also be taken into account, such as whether there is hot pursuit of a fleeing felon, a likelihood that evidence will be destroyed if police take the time to obtain a warrant, or a danger to police or other persons inside or outside the dwelling."

When the viewing of evidence takes place before any intrusion into a constitutionally protected area, a search has not occurred. However, a warrantless seizure of such evidence cannot be justified by the plain view alone. Thus, "in those cases in which the view precedes an intrusion into a constitutionally protected area the officer must be able to rely upon exigent circumstances . . . or he must obtain a warrant before he seizes the evidence." Officers lawfully on a defendant's grounds because of a recreational fire burning in violation of a local ordinance may, for example, observe slot machines in plain view inside a shed. But a seizure of the machines would require either a warrant or justification by way of another exception to the warrant requirement, such as exigent circumstances.

The Plain View Doctrine permits the warrantless seizure of evidence in plain view when (1) the officer has not violated the Fourth Amendment in arriving at the place from which the evidence could be plainly viewed, (2) the evidence's incriminating character is "immediately apparent" and (3) the officer has a lawful right of access to the object itself. Although inadvertence is a characteristic of most legitimate plain view seizures, it is not a necessary condition.

An unlawful arrest may result in suppression of any evidence recovered in a search incident to that arrest. However, police officers have statutory authority to arrest for misdemeanors committed in their presence.

When the circumstances do not support the conclusion that a search incident to arrest was necessary to prevent either harm to the arresting officers, the escape of the defendant, or the destruction of evidence, the search does not meet the exception to the warrant requirement. A search incident to arrest is justified by the rationales of ensuring officer safety and preventing the destruction of evidence. These justifications are not present if the burglaries with which the defendant was charged occurred nearly three weeks prior to the arrest and, at the time of the search, the defendant was handcuffed, the searched automobile was locked, and the automobile's keys were in the possession of the police.

The person of an individual may be lawfully searched, even without a search warrant, if the search is conducted incident to a lawful arrest. However, for such a search to be valid, it must be substantially contemporaneous with the arrest and confined to the immediate vicinity thereof. Blood alcohol content tests conducted without a warrant thirteen days prior to arrest are not sufficiently contemporaneous with the arrest to be "incident" to the arrest.

A warrantless search incident to defendant's constitutional arrest in a house on a burglary charge is unreasonable if it extends beyond the defendant's person and area from which he or she might have either obtained a weapon or destroyed something that could have been used as evidence against him or her.

A valid search incident to arrest must meet contemporaneity and proximity tests in relation to the arrest. A search conducted two hours before the arrest, while the police were waiting for the defendant to return home so that they could arrest him, is not valid. Furthermore, search of a bedroom is not incident to an arrest made on the porch.

Potential danger to police or the public satisfies the exigency requirement for warrantless vehicle searches in this Commonwealth, but a mere assertion of danger by an officer, without more, is insufficient to prove exigent circumstances.