Suppose two people are living together: the suspect and a tenant. If the tenant consents to a police search of the premises, then the police are not required to first obtain a warrant. What if the suspect and the tenant disagree, with the tenant granting permission while the suspect forbids the police to enter? Should the police be required to obtain a warrant before searching? Or what if the suspect denies permission to enter but the police go back later and the tenant consents?