Answer: The Fourth Amendment was involved, which protects against unreasonable searches and seizures. It may have been violated if the police did not have a warrant or probable cause to search Joe and the car.
Explanation: Arrest warrants serve the purpose of protecting people from unlawful arrests under the Fourth Amendment. The warrant also gives an actual notice to the person or persons being arrested about the charges pressed against them. Since it doesn't say the police had a warrant, that's a violation.