 Using the precedent set by the "Gerstein" case – in which the Supreme Court ruled that Florida's practice of keeping suspects for 30 days without probable cause was unconstitutional – and close interpretation of the Fourth Amendment, they found that the County of Riverside's practice of keeping suspects in lengthy custody without probable cause determination amounted to illegal detention (or held in custody without being charged).Illegal detention would unquestionably violate the unreasonable search and seizure clause of the Fourth Amendment.Withholding probable cause determinations from suspects for longer than 48 hours after arrest, absent exigent circumstances, would violate the Fourth Amendment.