Final answer:
The police officer's search of the car without warrant or consent is likely a violation of the driver's Fourth Amendment rights, and the evidence obtained may be considered inadmissible in court.
Step-by-step explanation:
In this scenario, the police officer stopped the vehicle for speeding and asked for consent to search the car. However, the driver refused to give consent. Without reasonable suspicion of any other crime, the officer called for a canine unit, which arrived five minutes later. The canine alerted to the presence of narcotics in the car, and marijuana was found.
Based on the information provided, the police officer's search of the car without a warrant or consent would likely be considered a violation of the driver's Fourth Amendment rights. In the case of Rodriguez v. United States (2015), the Supreme Court held that delaying a traffic stop to conduct a dog sniff without reasonable suspicion of other criminal activity is unconstitutional. Therefore, any evidence, such as the marijuana, obtained during the search would likely be considered inadmissible in court.