A search/seizure must be made with a valid W, which must be (1) issued by neutral, detached magistrate, (2) based on probable cause, and (3) described with particularity the place to be searched or item/person to be seized
Probable cause (PC): A fair probability that would warrant a reasonable person to conclude that evidence of a crime can be found at a particular place or that a particular Δ committed a crime
PC can be based on an informant's tip, which must meet the totality of the circumstances (TOTC) test: practical, common-sense considerations showing probability of criminal activity based on informant's veracity, basis of informant's knowledge, and corroboration from police investigation predictive information showing insider knowledge. May be based on an anonymous tip
PO must show recent facts, not hunches or "known for." To attack inaccuracies in a facially valid warrant, Δ must show material false statements made intentionally or recklessly (negligently OK)
Scope: Reasonably necessary to discover items. Must be executed w/o unreasonable delay while PC exists
Knock and announce rule: Police must give notice and wait a reasonable time before entering to execute W, except when there is RS that announcing will lead to destruction of evidence, endanger officers, or be futile
Good faith EXCEPTION to invalid W: Evidence or person seized via a facially valid (particular) but defective W is admissible if a reasonably well-trained PO acted in good faith thinking that the W was valid