In Warden, Maryland Penitentiary v. Hayden (1967) 387 U.S. 294, the United States Supreme Court found exigent circumstances justified the warrantless entry into a home. In that case, two cab drivers, who were alerted by shouts of a "holdup," followed an armed robbery suspect to a house and alerted police. (Id. at p. 297.) Police knocked on the door and were admitted by the defendant's wife; however, the court did not rely on consent when it later concluded that the exigencies of the situation justified the police action. (Id. at pp. 297-299 & fn. 4.) The Supreme Court explained that the police were informed that an armed robbery had taken place, and that the suspect had entered the house less than five minutes before they reached it. The court further noted that the police had acted reasonably when they entered the house and began to search for a man of the description they had been given and for weapons that he had used in the robbery or might use against them. (Id. at p. 298.) The court also clarified, "The Fourth Amendment does not require police officers to delay in the course of an investigation if to do so would gravely endanger their lives or the lives of others. Speed here was essential, and only a thorough search of the house for persons and weapons could have insured that the defendant was the only man present and that the police had control of all weapons which could be used against them or to effect an escape." (Id. at pp. 298-299.)