A lone gunman robbed an Amoco gasoline station and fatally shot the station manager. A police officer heard the police dispatcher's report and suspected Joseph Ecker. The officer and his partner drove immediately to Ecker's home, arriving at about the same time that an Oldsmobile arrived. The driver of the Oldsmobile took evasive action, and the car spun out of control and came to a stop. Two men fled the car on foot. Ecker, who was later identified as the gunman, was captured shortly thereafter inside his home. The second man escaped. Police found a sack of money and the murder weapon. They also found a title certificate with the name Rob Olson crossed out as a secured party, a letter addressed to a Roger R. Olson of 3151 Johnson Street, and a videotape rental receipt made out to Rob Olson and dated two days earlier. The police verified that a Robert Olson lived at 3151 Johnson Street. The next morning, a woman called the police and said that a man by the name of Rob drove the car in which the gas-station killer left the scene and that Rob was planning to leave town by bus. About noon, the same woman called again, gave her address and phone number, and said that a man named Rob had told a Maria and two other women, Louanne and Julie, that he was the driver in the Amoco robbery. Police officers at 2406 Fillmore to check out Louanne and Julie. The dwelling was a duplex and Louanne Bergstrom and her daughter Julie lived in the upper unit but were not home. Police spoke to Louanne's mother, Helen Niederhoffer, who lived in the lower unit. She confirmed that D had been staying upstairs but was not then in the unit. She promised to call the police when D returned. At 2 p.m., a pickup order, or 'probable cause arrest bulletin,' was issued for D's arrest. The police were instructed to stay away from the duplex. Niederhoffer called the police and said Olson had returned. Officers went to the house and surrounded it. The police then telephoned Julie and told her D should come out of the house. The detective heard a male voice say, 'tell them I left.' Julie stated that D had left, whereupon at 3 p.m. the detective ordered the police to enter the house. Without seeking permission and with weapons drawn, the police entered the upper unit and found D hiding in a closet. D made an inculpatory statement at police headquarters. The court denied D's motion to suppress his statement. The statement was admitted and D was convicted on one count of first-degree murder, three counts of armed robbery, and three counts of second-degree assault. The Minnesota Supreme Court reversed. It held that D had a sufficient interest in the Bergstrom home to challenge the legality of his warrantless arrest there, and that the arrest was illegal because there were no exigent circumstances to justify a warrantless entry. It held that D's statement was tainted by that illegality and should have been suppressed. P appealed.