When is physical evidence obtained during an unlawful arrest generally inadmissible?

Physical evidence obtained during an unlawful arrest is generally inadmissible when the arrest is made without a warrant. This is primarily rooted in the Fourth Amendment, which protects individuals from unreasonable searches and seizures. When an officer conducts an arrest without a warrant and without probable cause, it violates the due process rights of the individual. Consequently, any evidence collected as a result of that unlawful arrest is typically deemed inadmissible in court.

In essence, obtaining a warrant ensures that there has been a judicial review to establish probable cause before the deprivation of liberty occurs. Without this step, the legitimacy of the arrest and subsequent evidence is called into question, leading to its potential exclusion during legal proceedings. This principle upholds the integrity of the judicial system and protects citizens' rights against arbitrary law enforcement actions.