What is the plain view doctrine?

If the police are lawfully on the premises either to conduct a search or carry out an arrest, then they may seize evidence which is in plain view, even if the items are not within the suspect’s immediate control. However, the incriminating nature of the evidence in plain view must be readily apparent. The discovery of the evidence, however, does not have to be inadvertent. Plain view justifies only the seizure of the evidence; it does not support or justify the underlying search or arrest. To determine if the plain view doctrine applies, police must consider 1) are they lawfully on the premises pursuant to a valid search or arrest warrant or due to exigent circumstances? Is the evidence in plain view? And is the incriminating nature of the evidence readily apparent?