Is failure to comply with Brady Rules cause for a mistrial? The Legal Information Institute defines the Brady Rule as follows. Brady Rule Primary tabs The Brady Rule, named after Brady v. Maryland, 373 U.S. 83 (1963), requires prosecutors to disclose materially exculpatory evidence in the government's possession to the defense. A &quot;Brady material&quot; or evidence the prosecutor is required to disclose under this rule includes any evidence favorable to the accused--evidence that goes towards negating a defendant's guilt, that would reduce a defendant's potential sentence, or evidence going to the credibility of a witness. In regards to the issue of a credibility check of a witness. I f the government withholds information that is pertinent to the credibility of a witness is that cause for a mistrial? Does whether the government knowingly or unknowingly withheld this information influence whether a mistrial will be granted?
If the government withholds information that is pertinent to the credibility of a witness is that cause for a mistrial? Only if the error is not harmless under the standard applicable to evaluating harmless error in criminal cases (there is a voluminous case law on that point). Basically, it means that a new trial may be held and a conviction vacated on a charge against a particular defendant if there is a reasonable possibility that the withheld evidence, when considered in light of the total picture of evidence presented at trial, might have changed the outcome on guilt or innocence. Does whether the government knowingly or unknowingly withheld this information influence whether a mistrial will be granted? Not really. Knowledge is imputed. If someone in the prosecution team including the police knows, then it is known to the entire team for Brady purposes. If no one knew that it had the information (e.g. a key exculpatory document in possession of the prosecution was misfiled in one of dozens of bankers boxes of documents that it seized in a search and no one reviewed those particular boxes knowing to look for a document like that one or attuned to its potential significance, since it wasn't supposed to be in the place where it was filed), then it hasn't been withheld in the Brady sense unless someone specifically asked for the information in question with enough specificity that it could have been located if they looked at what they already had. The knowledge that must be disclosed is what the prosecutor's office or the police the prosecutor's office is working with knows. So, if a beat cop hides exculpatory evidence from the prosecutor's office, that is a Brady violation, but if the cops do a sloppy investigation that fails to reveal exculpatory evidence that is out there to be found, it isn't a Brady violation. Likewise, if a cop in another department halfway across the state knows something that impacts the credibility of a witness and the prosecutor is totally unaware of the existence of that information as are all the cops working on the case, then that isn't a Brady violation. What If It Isn't A Brady Violation? Exculpatory evidence discovered after the trial that isn't a Brady violation not to disclose may still be grounds for a new trial based upon newly discovered evidence in a motion for post-trial relief. But, the standard to get the court to grant a new trial based upon newly discovered evidence that was not withheld in a Brady violation is much more stringent than the mere harmless error standard. Instead: With a single exception, criminal defendants in the United States seeking a new trial based on newly discovered evidence are required to establish only that the new evidence makes it more likely than not that, in a new trial, they would be acquitted. Ohio requires clear and convincing evidence rather than a mere preponderance. There's a lot of case law on what constitutes newly discovered evidence which is &quot;new, material evidence that was unavailable at the time of the original trial[.]&quot; If evidence was available, but not used at trial, it can't be presented in a motion for new trial based upon newly discovered evidence. Often this means that it can't be considered even if the salience of the evidence previously available is only clear later in the light of other evidence that is genuinely newly discovered, or the defense attorney's failure to use that evidence in the first trial was negligent to a level constituting legal malpractice.
Your question is essentially this: consider a defamation lawsuit in which A alleges that B falsely stated that A did X (and it is not contested that B made the statement) also consider that B has done X in the past is it of any relevance to A's defamation suit that B has done X in the past canada Evidence must be relevant to a live, material issue In order for evidence to be admissible it must be &quot;relevant to a live, material issue in the case&quot; (this is from a dissent, but there is no disagreement about this point). Stage 1: Did B make a defamatory statement about A that was published - no relevance to this issue Defamation is prima facie proven if B's statement was published and if it tended to lower the reputation of A. The fact that B has done X in the past is irrelevant to this aspect of the analysis, especially when the defendant is not alleging that they did not say &quot;A did X.&quot; Stage 2: Defences - there is a very narrow path for relevance on this issue Once defamation is prima facie proven, the burden flips to the defendant to establish a defence. Of all the possible defences, the only one in which I could see B having done X in the past being relevant is the defence of fair comment: (a) the comment must be on a matter of public interest; (b) the comment must be based on fact; (c) the comment, though it can include inferences of fact, must be recognisable as comment; (d) the comment must satisfy the following objective test: could any [person] honestly express that opinion on the proved facts? (e) even though the comment satisfies the objective test the defence can be defeated if the plaintiff proves that the defendant was [subjectively] actuated by express malice. The fact the B has done X in the past could be relevant to this defence if B were to use that familiarity with the activity X as part of the commentary on why they believe that A has done X. It could also be relevant (not on its own, but along with much more context) for an allegation of malice on B's part. Conclusion: Evidence that B did X in the past would likely not be relevant I see it very unlikely that B having done X in the past would be relevant. It would likely be treated as a collateral issue, unless B's credibility somehow became absolutely central to the litigation and if the judge was convinced that such acts relate to credibility. On the facts as described, and even for a fair comment defence, I don't see that being the case.
The first thing to keep in mind is that, before appearing on the stand, an expert witness will have given a sworn deposition and delivered a written report of his or her findings. They could expect to be questioned about anything they say under oath that contradicts something else they said under oath. It’s not illegal for an expert to admit they were wrong before, or that there are other facts that support a different conclusion—indeed, a witness on the stand might be obligated to—but it might not do their professional reputation and their credibility with the jury any good, either. In the U.S., the opposing counsel is generally allowed to contact a witness, and take a statement, but may not ask the witness to testify falsely or offer any inducement prohibited by law. (See Supreme Court Rule (SCR) 173/Model Rule (MR) 3.4.) It would certainly be illegal for a witness to take money from both parties in the case without informing them or the court, or to swear that whatever the highest bidder pays them to say is their expert opinion. If this happened under direct examination, the lawyer would probably cut their losses by asking no further questions and getting the witness off the stand. Putting the witness on the stand would give the other side an opportunity to cross-examine them. Grilling your own expert as a hostile witness, even if the judge allowed it, would only make your position seem tendentious. Nothing stops an expert witness from giving testimony that is more helpful to the other side. They are witnesses, not lawyers, and their duty is to tell the truth, not to zealously advocate on behalf of some client.
Generally speaking, witnesses are not legally represented at trial, unless they are also parties. While a witness may choose to seek legal advice about a request or order they have received to give evidence, they would generally be expected to take this opportunity before they actually show up at trial. A witness examination would not normally be adjourned because a witness said something damaging to their own credibility or to one party’s case, and would like to pause and obtain legal advice. One goal of cross-examination is to expose unreliable evidence by obtaining this kind of tactical advantage over a witness. It is up to the party whose case was damaged to try to fix the problem in re-examination or reply evidence. That party may not be particularly interested in protecting the witness’s personal interests. There may be exceptions in specific factual situations, when it becomes clear that a witness does not understand their right to object to giving evidence on the grounds of self-incrimination or some other privilege. A judge may choose to halt further questioning of the witness if there is a real risk of a mistrial or some other procedural unfairness, which can be addressed without unfairly depriving the cross-examiner of their opportunity to challenge the evidence.
There are instances when the testimony may still be admitted. For example, a deposition may be admitted at trial either for impeaching or when a witness cannot attend, which involves the circumstance of death (FRCP 32(a)(4)(a)). Additionally, regarding hearsay, there are numerous exceptions. My Evidence professor said in class "If you cannot find a way to get evidence around a hearsay objection, you are not trying hard enough." One such hearsay exception states in the committee notes: Accordingly, the committee has amended rule 803(8) to refer to the provision of [proposed] rule 804(b)(5) [deleted], which allows the admission of such reports, records or other statements where the police officer or other law enforcement officer is unavailable because of death, then existing physical or mental illness or infirmity, or not being successfully subject to legal process.
What are the ethical rules that limit interaction between civil and criminal proceedings on the same facts? A private lawyer's job is to look out for the client's interests before the public interest in these cases. In many states, a private lawyer is not permitted to threaten to seek a criminal prosecution to gain an advantage in a civil action. A private lawyer, myself included, will often deliberately not pursue criminal charges in order to not impair the ability of a client to collect a judgment. A prosecutor has wide discretion to prosecute or not when the prosecutor is aware of a crime that there is probable cause to believe was committed. A complaint by the victim is not required in the U.S., but most prosecutors consider a victim's wishes. A prosecutor may ethically make prosecution dependent upon making a victim whole. So is this conflict and result just an "unfair" fact of all common-law justice? What is "fair" is beyond the scope of Law.SE which deals in "what is", not in what is "fair". Or are there mechanisms that exist to satisfy the demands of justice despite this conflict? Not really. Just the good judgment of the individual actors in the system given their respective duties and roles.
The answer by @A.fm. isn't wrong, but it also is unduly optimistic. In my experience, in real life, people are more likely to lie when they are under oath than when they are not under oath, and law enforcement officers tend to be particularly good at lying on the stand because they testify frequently in court cases. In almost all places in the United States (and most foreign jurisdictions), in a pure battle of credibility in the eyes of a judge or jury between a law enforcement officer and an individual citizen charged with a crime, the law enforcement officer's account is going to be found to be more credible (beyond a reasonable doubt) about 90% of the time or more, unless you have a majority-minority jury or an outlier extremely liberal judge or the law enforcement officer has a personal involvement in the case (e.g. it involves a family member of the officer). The likelihood that it will be resolved one way or the other does depend significantly on race and social class, however. The credibility imbalance is still great and favors law enforcement, but not as extreme, when it is between an unrelated third-party witness and a law enforcement officer. In the absence of hard evidence or a law enforcement insider witness willing to testify in your favor, it is almost impossible to win a credibility contest in a case like the ones you suggest. One important step an attorney can take, however, is to seek discovery on any prior instance in which the testifying officer has been disciplined for untruthfulness or had his testimony in court found to be untruthful. This will usually be fruitless, but levels the playing field to closer to 50-50 if you get lucky and received such evidence. Such a request also provides a means of collateral attack on a conviction if the law enforcement officer has a history of untruthfulness that wasn't disclosed by the prosecution after such a request is made by a defense lawyer. So, what does protect you? Mostly the desire of the bosses of law enforcement officers (who are ultimately politicians, mostly local politicians in the United States) to see the law enforced in a non-corrupt manner and the fear of a law enforcement officer that he or she might be found to have lied using physical evidence unknown to him at the time (like a secret recording of an interaction). Law enforcement officers usually don't have much to gain from lying (although this equation changes a law when police department can receive assets seized in civil forfeitures that they are involved in) and usually they want people who are "bad guys" to be in jail to protect "good guys" although they aren't always very concerned about the means by which they achieve these ends. Of course, "usually" is a weasel word here and there are many exceptions that crop up in real life (e.g. when police have engaged in misconduct and want to protect themselves from the consequences of that misconduct). The other obvious solution (so common that in certain eras of U.S. history there were travel guides targeted at African-American motorists to help they carry out this approach) is to avoid places with police who have historically been corrupt. The United States has a uniquely bottom heavy law enforcement structure. Something on the order of 95% of law enforcement officers are employed by local governments or are otherwise tightly constricted geographically (e.g. rangers in national or state parks). And, even the small number of state law enforcement officers are heavily concentrated doing traffic enforcement on major state and federal highways. Similarly, lots of federal law enforcement agencies are broken up into geographic divisions some of which are known to be more corrupt than others (e.g. there is more corruption in the border patrol on parts of the border with Mexico than on most of the border with Canada). So, if you want to avoid the risk of encountering bad cops, stay away from places that are known to have bad cops. The solution may seem like a "cop out" (sorry, pun intended), but it is actually a pretty unique feature of the American law enforcement system. Most countries (e.g. the U.K., South Korea, Russia, Japan, Spain, Mexico, France) have a much more centralized law enforcement bureaucracy, which is fine when the people are the top are scrupulously non-corrupt, but which also makes it much easier for the rot of corruption to become geographically widespread and hence unavoidable from the point of view of an individual citizen. In contrast, in the U.S., even in the most corrupt of times (e.g. the Prohibition era), there are almost always many jurisdictions where law enforcement is not corrupt and corrupting the entirely system is much more difficult than in most countries.
Police reports are treated as &quot;Business Records&quot; and are therefore not excluded by the hearsay rule, regardless of the availability of the declarant. Federal Rules of Evidence, Rule 803: Exceptions to the Rule Against Hearsay Business Records Exception The following are not excluded by the hearsay rule, even though the declarant is available as a witness: Records of regularly conducted activity. A memorandum, report, record, or data compilation, in any form, of acts, events, conditions, opinions, or diagnoses, made at or near the time by, or from information transmitted by, a person with knowledge, if kept in the course of a regularly conducted business activity, and if it was the regular practice of that business activity to make the memorandum, report, record or data compilation, all as shown by the testimony of the custodian or other qualified witness, or by certification that complies with Rule 902(11), Rule 902(12), or a statute permitting certification, unless the source of information or the method or circumstances of preparation indicate lack of trustworthiness. I suppose a valid defense in this case would be to bring into question the &quot;trustworthiness of the preparation&quot; (via 803(8)(B)), but it is still admissible. Admissibility of Police Reports A number of courts have held that a police report otherwise excluded by Rule 803(8) is admissible under the hearsay exception for recorded recollection in Rule 803(5). On the other hand... At least one court has held that the recorded recollection exception does not allow the admission of a police report that is excluded by Rule 803(8). Offering another reason for the exclusion, the court observed that such reports, particularly when they concern on-the-scene investigations, are considered less reliable than records prepared by other public officials because of the adversarial nature of the confrontation between the police and the defendant in criminal cases and the likelihood of the report’s use in litigation. See United States v. Pena-Gutierrez, 222 F.3d 1080, 1086–87 (9th Cir. 2000); see also State v. Harper, 96 N.C. App. 36, 40–41(1989) (recognizing this rationale in finding police report inadmissible under Rule 803(8); court did not address admissibility under other rules). Recognizes the conflict of interest police have when recording evidence against a defendant, so it may be possible to argue admissibility in that way, but it seems most courts do not follow this line of thinking.