What did the Hudson v Michigan ruling establish regarding the "knock-and-announce" rule?

The Hudson v. Michigan ruling clarified that violations of the "knock-and-announce" rule do not automatically invalidate evidence obtained during the subsequent search. The Supreme Court determined that the rationale behind the knock-and-announce rule, primarily aimed at protecting privacy and preventing violence, does not outweigh the need for law enforcement to effectively conduct searches. As a result, evidence collected after a breach of this rule may still be admissible in court. This ruling is significant because it emphasizes the importance of balancing the rights of individuals with the operational needs of law enforcement, affirming that not all procedural missteps during a search lead to the suppression of evidence.