Jury deciding Reasonable Search
The issues of whether a search is reasonable, whether it violates the Fourth or Fifth amendments, and whether evidence should be suppressed, have been considered issues of law, or mixed issues of law and fact by US courts. Indeed I can not find a single case where such a decision was given to a jury.
It might be argued that such a decision should be put to a jury, or that the jury should find facts (such as whether a search was "reasonable", or made "in good faith", or whether a police officer was telling the truth about the events of an arrest and search). But the Anglo-American common law system has not historically put such issues to a jury, and it does not do so now. Partly this is to ensure a degree of consistency in the legal decisions, partly it is a relic of a distrust in the ability of a jury to decide any issue more complex than "yes or no", partly it is a matter of procedural convenience: having a separate jury to hear and decide suppression issues during a pre-trial proceeding would add significant time and complication to deciding cases where such issues arise (and they often do) and partly it is just a mater of tradition.
Congress or a state legislature could mandate that such issues be decided by a jury. None have. The federal or state constitutions could confide such issues to jury decision, in whole or in part. None have. So that is just how US law is at this time. It could be changed.
Direct vs Delayed effect of Constitutional Rights
Several Constitutional provisions can operate during trial, indeed any claim that an accused person's constitutional rights must be made at the trial (or in pre-trial motions) or it will be deemed waived, such a claim normally cannot be asserted for the fist tiem on appeal.
What can be confusing is that we only read opinions in which a trial court denied such claims and an appeals court is asked to overturn the conviction because rights were denied.
If the right is upheld either there will be no appeal, or the right will not be an issue in any appeal, which will be on some other ground.
The Fifth amendment rights to Due process and silence, the right not to engage in self-incrimination, and the Fourth amendment right against unreasonable searches and seizure are the most frequently invoked rights in criminal trials. The sixth amendment right to a jury has often been invoked and has led to verdicts being overturned. The right, established in Brady v Maryland for the defense to get all possibly exculpatory informational known to the prosecution also plays a very direct role in many trials. This is also founded on the Due process clause. Eighth amendment rights against excessive bail are also procedural and often come up in pre-trial proceedings, while the right against cruel and unusual punishment tends to appear at a later stage.
The First and Sixth combine to grant the right to an open an public trial, again a procedural right at trial time.
Other rights, such as free-speech and free-exercise rights (1st amendment), right to bear arms (2nd), rights to assemble and petition, free press rights, rights to travel, etc usually come up in a substantive context, that is an accused claims that a law s/he is accused of violating infringed one of these rights. But that claim is still raised at the trial stage.
Again we read case law on such rights only where they were denied at a trial level and there is an appeal challanging such a denial.
Recent Modifications of the Exclusionary Rule
Hudson v. Michigan
In Hudson v. Michigan 547 U.S. 586 (2006) The US Supreme Court overturned, in a 5-4 ruling, the application of the Exclusionary Rule to violations of the "knock and announce" rule. This rule requires police officers, in the absence of a special "no-knock" warrant, to knock and announce themselves before entering a dwelling, even with a search warrant. The majority opinion said that the rule was still valid, and might be the basis of a suit under 18 USC 1983, but that such violations were not frequent enough nor serious enough to justify applying the Exclusionary Rule to them. They asserted that internal police policy enforcement and the possibility of civil (sec 1983) suits would be enough to avoid serious problems. hey did no alter any other aspect or application of the Exclusionary Rule. Justice Kennedy said, in his concurring opinion, that if a pattern of such violations developed, he might change his view. Thr minority asserted that civil suits did not result in significant damages in such cases, and would not serve as an effective deterrent to violations of the "knock and announce" rule.
Utah v. Strieff
In Utah v. Strieff, 136 S. Ct. 2056 (2016), police officers were watching a suspected house. They saw a man (who proved to be Strieff) come out of the house. An officer stopped Strieff on the street and executed an "investigatory detention"; after asking Strieff for identification, officers learned that Strieff had an outstanding warrant for a traffic violation out against him. They arrested him and searched him in connection with the arrest, finding drug paraphernalia and methamphetamine.
At his trial Strieff moved to suppress the evidence on the ground that there was no valid basis for the investigatory detention, because the officers did not have reasonable suspicion. The evidence was not suppressed, Strieff was convicted, and appealed. When the case gor to the Supreme Court, the majority held that the investigatory detention was improper, but because there was a valid pre-existing arrest warrant for Strieff, the arrest was proper, and the search went with the arrest. They held that the improper detention was not a reason to invoke the Exclusionary Rule, because the arrest was proper and that is what triggered the search. This was again a 5-4 decision. It did not change the Exclusionary Rule, but meant that in certain situations it would not apply.
The Exclusionary Rule was created in large measure to deter unlawful and improper police an official actions, particularly interrogation by torture and unauthorized searches without probable cause. It ws also created on the theory that if a court admitted evidence obtained by illegal acts, it became complicit in those acts.
In the absence of such a rule, other methods must be used to prevent or deal with official overreach and the tendency of government to ignore the law in pursuit of those believed to be wrongdoers.
In theory a strong policy and practice of not allowing police to take such actions, and disciplining or dismissing those who violate such laws could achieve this end. In practice it has not done so. While the kind of blatant brutal interrogation found unlawful in Brown v. Mississippi, 297 U.S. 278 (1936) may be less common now than it was in 1936,allegations of police misconduct and clear violations of the rights of the accused continue to be discovered.
In theory civil suits could penalize officers who act lawlessly, but in the US the defense of qualified immunity has made this of limited value, and in any case a successful section 1983 suit will not overturn a conviction.
No other device for restraining official zeal has yet been found so effective.
Those who favor restricting or eliminating the Exclusionary Rule claim that modern training and the increased professionalism of the police have obviated the need for teh Rule. Those who favor maintaining the Rule point to instances were police misconduct nonetheless occurred, and civil suits did not provide an effective remedy. They aklso claim that with proper police work many of those whose rights have been violated could and would have been convicted without such violations. (For example, Miranda was convicted on a retrial without the excluded confession.) There seems little prospect of agreement between those who hold such differing views.