Part I of this note discusses the Fourth Amendment’s protection against unreasonable search and seizures and its probable cause requirement. The Fourth Amendment’s text remains the same since its enactment. However, interpretation of the Fourth Amendment continues to evolve in order to stay current with society. Interpretation of the Fourth Amendment also varies based on state constitutional law since states can provide its citizens with greater protection than the United States Constitution. This is why the United States Supreme Court, federal district courts, and state courts have all undergone thorough Fourth Amendment analyses when applying the true meaning of the Fourth Amendment to the advanced issue of cell phone searches.

At first, Riley’s groundbreaking holding seems like a bright- line rule for law enforcement and courts to follow. However, the decision left open areas for additional legal analysis. For example, how does the Riley decision effect the issue of establishing probable cause? Part II of this note addresses the Fourth Amendment’s probable cause requirement. Specifically, this note discusses how the Riley decision lacks guidance to determine what is sufficient to establish probable cause to obtain a warrant to search a cell phone. Under United States constitutional law, courts apply a totality of the circumstances approach to determine if probable cause exists. However, some states, like New York, reject the totality of the circumstances approach and apply a strict Aguilar-Spinelli analysis to determine probable cause.