1. Ken is walking in a train station, carrying a briefcase. The police have probable cause to believe there are drugs in the briefcase. The police follow him out of the train station. Ken walks towards a park. At the entrance of the park, the police stop Ken and search the briefcase without a warrant. The police find drugs in the briefcase. Ken challenges the search, claiming the search is illegal for the police have no search warrant to search the briefcase. Is the search of the briefcase illegal?

2. Ben arrives at Boston airport in a flight from Florida. The police have probable cause to believe there are drugs in Ben's carry-on suitcase. Ben walks to the parking lot. He puts the suitcase inside the car and drives away. Five minutes into his driving, the police stop his car. The police locate the suitcase in the car and search it without a warrant. They find drugs in it. Ben challenges the search. He claims that the search of his suitcase is illegal for the police cannot search a container without a warrant. Is the search of the suitcase illegal?

3. The same facts as in the above case scenario but add the following. After the police search the suitcase and find the drugs, they search the entire car. Under the seat of the passenger compartment the police find an illegal gun. Ben challenges the search, claiming the search of the passenger compartment is illegal. Is the search of the passenger compartment illegal?

4. Suppose Ben does not go to the parking lot to drive his car. He decides to walk home. Is there a way for the police to legally search his suitcase without a warrant?