Highway patrol officer Tom stopped a vehicle on the freeway for speeding. Prior to issuing a ticket for speeding, Officer Tom looked around the car and asked the driver to open the glove compartment. The driver voluntarily complied. Drugs were found in the glove compartment. Officer Tom then arrested the driver and searched the whole car, including a briefcase marked "private" that was found in the trunk of the car. Was the search of the trunk valid?  Was the search of the briefcase valid?  Justify your answers.