What is a commonly accepted reason for warrantless searches?

Warrantless searches are permissible under certain circumstances, and one commonly accepted reason is the plain view doctrine. This legal principle allows law enforcement officers to seize evidence of a crime without a warrant if they are in a location where they have a right to be and they observe illegal items or evidence of a crime in plain sight. The rationale behind this doctrine is that since the officer is lawfully present and can immediately see the evidence without any further search, there is no expectation of privacy or need for a warrant.

In contrast, suspicion of drug use does not alone justify a warrantless search; specific evidence or circumstances must support the suspicion. Similarly, simply the presence of a known criminal does not provide sufficient legal grounds for a warrantless search unless there are observable factors that indicate criminal activity. Lastly, routine traffic stop procedures may allow for limited investigative actions, but they do not inherently permit warrantless searches unless additional probable cause arises during the stop.