In the case of James v. Louisiana in 1965, the U.S Supreme Court ruled on a matter involving illegal search and seizure. The petitioner, James, was convicted for possession of policy slips based on evidence seized during an unlawful police raid at his home without a warrant. He appealed to the Supreme Court arguing that this violated his Fourth Amendment rights against unreasonable searches and seizures. The court agreed with him unanimously (9-0), reversing his conviction and remanding it back to state courts for further proceedings consistent with their opinion. They held that regardless of whether or not contraband materials were involved, any evidence obtained through an unconstitutional search could not be used in court as per the exclusionary rule established by Mapp v Ohio (1961). This decision reinforced citizens' constitutional protections from unwarranted intrusions into their privacy by law enforcement officials.

In the dissenting opinion for James v. Louisiana, it was argued that the majority's decision to overturn a conviction based on an illegal search and seizure violated established precedent. The dissenters contended that while there may have been procedural errors in obtaining evidence, these did not necessarily invalidate its use in court. They pointed out that previous cases had allowed illegally obtained evidence if it could be proven beyond reasonable doubt that such evidence would have inevitably been discovered by lawful means. Therefore, they believed this case should not be treated differently from those precedents simply because of potential police misconduct or negligence during investigation procedures. Furthermore, they expressed concern about the implications of excluding all unlawfully obtained evidence without considering other factors like inevitability of discovery or good faith mistakes by law enforcement officers which might undermine effective crime control efforts and potentially encourage criminals to exploit legal technicalities for their advantage.