Final answer:
Crime scenes often have physical evidence that can provide vital clues in solving crimes. Accessing data on a cell phone requires a search warrant to protect individuals' rights. Various court cases have established the legal requirements for obtaining a warrant.
Step-by-step explanation:
Crime scenes commonly contain physical evidence such as fingerprints, footprints, hair, fibers, or biological material like blood or semen. These can be collected and used as vital evidence in solving crimes. However, accessing information contained in a cell phone requires a search warrant, as established in court cases like Riley v. California. The Fourth Amendment of the U.S. Constitution protects individuals from unreasonable searches and seizures, requiring law enforcement officers to obtain a warrant based on probable cause.