What prevents someone from claiming to be the murderer in order to get the real murderer off? Say someone is on trial for a murder they committed. During the trial, one of the witnesses, a friend of the defendant, admits that it was actually they who were the killer. It seems that this would be enough to create reasonable doubt and get an acquittal, or even possibly have the state drop the charges because they now believe that they should be charging this other person. After the trial ends, the friend presents irrefutable proof that they weren't actually the murderer. Of course, this friend could be charged with perjury, obstruction, etc... but the original defendant can't be re-tried for the murder because of double jeopardy, and their friend can't be tried (or won't be found guilty) because of the evidence that he didn't do it. Is there a flaw in this system? Something that prevents someone from actually doing this? Related: Can someone get protection under Double Jeopardy for a crime by arranging to be put on trial with fake evidence that is then disproven? Side-note; something just like this happened in an episode of Law and Order; though I had been wondering about this long before seeing that.
It is not as simple as the witness just making the assertion that they are the killer. They will be subject to grueling cross examination to break their story. If the victim was killed at a specific time, perhaps the prosecution can prove the witness was somewhere else at that time, and therefore lying. (No Opportunity) If the victim was killed with a specific weapon, perhaps the prosecution can prove that only the accused had the weapon, and the witness had no access to it, and therefore lying. (No Means) If the victim was killed in a specific way, perhaps the witness doesn't know any of the details of how the crime happened, and therefore is not credible. (No Knowledge) If the accused's DNA is found at the scene, and their shirt is covered in blood, and the witness has no corroborating evidence against them, then the witness is likely lying. (No Evidence) If the witness claims he is the murderer, the prosecution can inquire as to why he killed the victim. The real murderer had a reason: Perhaps money, power, hatred, passion, etc, that the witness may not be able to provide. (No Motive) Planting doubt in the mind of a jury is an effective defense. But lying about who did what, when, how, and why it is not as easy as you suggest.
How exactly would the court determine this to be the cause of divorce? 99.99% of the time, this would be purely a &quot;he said she said&quot; situation, for how can someone prove refusal to engage? You can prove the opposite if there are children born to both parents, but how can one prove a negative? Or is the statement by the divorce initiator considered sufficient for the judge? Testimony under oath is evidence. Judges resolve &quot;he said she said&quot; situations every day on a routine basis with witness testimony alone by judging the credibility of each witness before them. See also an answer by @Jen about the subject of how things are proved in court in general. In the appropriate case, testimony under oath with no other corroborating evidence can even support a murder conviction as proof beyond a reasonable doubt. It can certainly suffice to prove marital fault in a civil lawsuit for a divorce. If the judge finds that witness testimony under oath between more than one witness is irreconcilably different, and each witness is equally credible, and that it is impossible to tell which person is telling the truth, then the person seeking relief from the court has failed to meet their burden of proof to obtain relief from the court. But, this is rare. Usually, when witnesses are both testifying under oath and disagree about what happened, the judge will find that one witness is more credible than the other. And, in truth, while people certainly do lie in open court under oath, and probably are more likely to lie in that situation than when speaking to someone not under oath outside of a courtroom, most of the time, people don't lie and the testimony of all of the witnesses are consistent with each other subject to limitations based upon what they could perceive from their perspective and the limitations of imperfect memories. This could come down to demeanor in court, hesitation in answering, &quot;tells&quot;, inconsistencies in their testimony, corroboration from other evidence and other witnesses (e.g. what someone said to a friend or wrote in a diary at the time), evidence that a witness has been convicted of a crime of deceit in the past, use of language that suggests coaching about their testimony, or common sense judgments about whose story seems more plausible under the circumstances of the parties in front of the judge.
Neither with or without a warrant, if the confession is all there is. For a felony, the question is whether there is probable cause (4th Amendment). This is true whether the police arrest you, or they get a warrant – the difference being that in the latter case the warrant is issued by a guy with much greater knowledge of what constitutes probable cause. The question then would be whether a confession alone constitutes probable cause. There is a venerable rule, the corpus delecti rule (300+ years old) that requires there to be independent evidence of a crime, the point of this rule being to to prevent mentally ill people from being convicted of a crime that never even happened. Under that rule, a confession alone would not be probable cause (but a confession and a bloody glove could be). This article reports that at the federal level and in 10 states, there is a lower bar of mere "corroboration" without the need to argue that there was an actual crime. Exemplifying this relaxing of the traditional rule, in Opper v. United States, 348 U.S. 84, the court held that "[a]n accused's extrajudicial admissions of essential facts or elements of the crime, made subsequent to the crime, are of the same character as confessions, and corroboration by independent evidence is required". However, "[t]he corroborative evidence need not be sufficient, independent of the statements, to establish the corpus delicti" and "[i]t is sufficient if the corroboration supports the essential facts admitted sufficiently to justify a jury inference of their truth; but those facts plus the other evidence must be sufficient to find guilt beyond a reasonable doubt". In such jurisdictions, courts take a "totality of circumstances" approach focusing on whether the confession is trustworthy.
It depends on what the jury said, and if it's criminal or civil. In criminal cases, the judge may almost never set aside a verdict of acquittal. There is a single case in the US in which this happened, and it was a bench trial (no jury). That case featured the defendant bribing his trial judge; the Seventh Circuit held that he was never in jeopardy due to the bribe. As far as I can tell, that's the only one. There have been no cases that I can find of a jury's verdict of acquittal being overturnable. Judges can poll the jury to make sure they're unanimous (at least in federal court), and if they aren't then it's a mistrial, but that's because the jury was never in agreement in the first place. On the other hand, a judge has several ways to enforce an acquittal. In federal court, for instance, the defense can move for a motion of acquittal either before or after the case goes to the jury. If the motion is granted before the verdict, double jeopardy applies to retrial. If it's granted after a conviction, then the judicial acquittal can be reversed on appeal, possibly requiring a new trial. Before the verdict is returned, the judge can declare a mistrial. After the verdict is returned, it's too late for that. In civil cases, things are more complicated: double jeopardy does not exist there. There, there is a notion of a judgment as a matter of law: the judge determines that, based on evidence presented, no reasonable jury could possibly find the other way. This can happen before or after the verdict, and is appealable.
There are great jurisdiction by jurisdiction differences in the statutes of limitations that apply to crimes. Some jurisdictions have no statute of limitations for any serious crime (e.g. Canada and if I recall correctly Virginia). Others have statutes of limitations for almost all serious crimes other than murder (e.g. Colorado). Where there is a statute of limitations, the primary issue is that the ability of the prosecution and defense to secure reliable evidence that will allow a jury to enter an accurate verdict. This potential to conduct a fair trial can be compromised by a delay in pressing charges. Alibi witnesses can die or disappear to someplace that they can't be located, the location of the alleged crime can change in ways pertinent to proof, memories of witnesses in general can fade. Records or correspondence that could show intent can be destroyed. This is particularly a burden for an innocent criminal defendant who did not know that he or she needed to prepare a defense and gather evidence to respond to criminal charges. Some states toll statutes of limitations during a period of a victims minority or incapacity when brining charges may not be feasible. Other states have a long statute of limitations in rape cases where there is DNA evidence available that can conclusively tie a defendant to the scene of the crime (lack of consent would still have to be established), but a shorter statute of limitations in other rape cases. Murder and fraud are the most common offenses to lack a statute of limitations, in the first case, because it is considered the most serious crime and because the victim is unable to report the crime, and in the latter case, because fraud, by its nature and by the perpetrator's design, may go undiscovered for very long periods of time. Is there a line of reasoning to decide which classes of crime have a limited window for prosecution? While I've given some examples of the considerations that apply, ultimately, this is a legislative and political decision and not a legal one. You can't determine by reason alone which classes of crimes will have a limited window for prosecution. Different legislative bodies make different decisions on the same issues at different times and in different places.
united-states Procedures differ on such things. The closest I know of to an outcome of "not enough evidence" is the classic "scotch verdict" of "Not Proven. In the US, the prosecutor can wait to proceed with a criminal case while s/he does (or has done) as much investigation as s/he thinks is advisable. But once the trial starts, it normally proceeds to a conclusion. If there is not enough evidence to convict, the result should be "not guilty" and that will bar any future trial of the same person for the same offense under the doctrine of Double Jeopardy. Circumstantial evidence, as described in the question, can be enough to convict, if the jury (or judge in a bench trial) is convinced beyond a reasonable doubt that the accused is guilty. Exactly how much evidence it takes to convince a Jury varies, and there is not a clear standard other than the phrase " beyond a reasonable doubt". The judge, or a later appeals court, can set aside a jury verdict for insufficient evidence, but only by finding that no reasonable jury could have convicted on the evidence pre3sented, taking it in the light most favorable to conviction. Judges are reluctant to set aside jury verdicts unless they appear badly wrong. If further evidence is found during the trial, which tends to show the accused is not guilty, the prosecutor can request that the trial be halted. This may or may not bar a future re-trial of the same defendant, depending on whether the dismissal is 'without prejudice", a decision the Judge makes. But once evidence has been started to be presented, dismissals are usually "with prejudice" meaning that double jeopardy applies. The defense can also request a dismissal, most often at the end of the prosecution case. In rare circumstances the Judge may dismiss without a request from either prosecution or defense. These will most often be "with prejudice" It is possible for the trial to be recessed while new evidence is evaluated or sought, but this is rare and usually only for a short time -- a day or two, perhaps. In general a prosecutor is not supposed to schedule a trial if there is any reasonable chance of additional evidence coming to light. It can and does happen, but the system tries to avoid it, and does not easily accept that it has happened. This answer is US-Specific, and different answers may apply in other places.
That's basically correct. The Double Jeopardy clause prevents the federal and state governments from trying you again for a crime that you've already been acquitted of, no matter what new evidence turns up. Even if you confessed to the crime, you could still not be tried. The relevant text of the Fifth Amendment reads: No person shall ... be subject for the same offence to be twice put in jeopardy of life or limb. The case of Mel Ignatow is probably among the most famous examples. He was charged with murdering a woman, but acquitted at trial. About a year later, a guy laying carpet at his house pulled up floorboards and found the victim's jewelry, along with pictures of Ignatow murdering the victim. Ignatow confessed, but the state couldn't charge him with murder again, though they could charge him perjury for testifying that he hadn't killed her. So the answer is yes, the Fifth Amendment generally prevents the government from trying you for a crime you've been acquitted of. There are two main caveats here. First is the dual-sovereignty principle, which accounts for the fact that almost anywhere that the Fifth Amendment applies, a person is subject to the laws of two sovereign governments: the federal government and that of whatever state the person is in. For example, robbing a bank in Los Angeles would violate the laws of both the United States and California. If California put you on trial, but you were acquitted, the Double Jeopardy Clause would bar California from trying you again, but it would not be a defense if the federal government wanted to try to charge you again. Second is the language about &quot;the same offence,&quot; which is not as clear as it might sound at first. In the course of committing a crime, a person can easily commit many other crimes without thinking of it. In your bank robbery, for instance, you could easily break the following additional laws: trespassing, menacing, carrying a concealed weapon, brandishing a firearm, larceny, grand larceny. This raises the question of what affect your acquittal on the robbery charge has on the possibility of charging you on these other offenses. The answer can be found in Blockburger v. United States, 284 U.S. 299, 304 (1932): The applicable rule is that, where the same act or transaction constitutes a violation of two distinct statutory provisions, the test to be applied to determine whether there are two offenses or only one is whether each provision requires proof of an additional fact which the other does not. This is easier to understand in practice than in theory. If you want to bring charges for the same conduct without violating the Double Jeopardy Clause, you need to be able to make a Venn diagram where the first charge and the new charge each has at least one element that the other does not. So map out the following possible offenses involved in a robbery: theft: unlawfully taking the property of another person aggravated theft: unlawfully taking the property of another person, when the property is worth more than $1,000 menacing: threatening to injure another person aggravated menacing: threatening to injure another person while brandishing a deadly weapon robbery: unlawfully taking the property of another person, facilitated by a threat to injure another person aggravated robbery: unlawfully taking the property of another person, facilitated by a threat to injure another person while brandishing a deadly weapon So now you have a Venn diagram that looks like this: If you've been acquitted of robbery, a prosecutor who wants to charge you again needs to find an offense that (1) requires proof of a fact that robbery did not, and (2) does not require proof of a fact that robbery did. This means the prosecutor can't bring a charge for the &quot;greater offense&quot; of aggravated robbery, because the earlier robbery charge didn't require proof of anything that aggravated robbery would not. The prosecutor also can't bring a charge for theft or menacing, because neither requires proof of anything that robbery did not. These are called &quot;lesser included offenses.&quot; But a charge for aggravated theft would be allowed. Although there's a shared element between aggravated theft and robbery (taking the property of another), there are also unique elements to both aggravated theft (property worth more than $1,000) and robbery (a threat to injure another). A charge for aggravated menacing would also be allowed, as it requires proof of brandishing a deadly weapon, but does not require proof of taking the property of another.
Carl may not do this, as he would be prohibited from making this argument at trial. At trial, evidence must be relevant, meaning that it makes a fact of consequence more or less likely to be true. Because the trial is meant to determine whether Carl is or is not guilty, his promises of future philanthropy have no bearing on the matter. And even if they somehow did, Carl still would not be able to tell the jury about them because they would be blocked under Rule 403, which excludes evidence because its probative value is substantially outweighed by its risk of biasing or confusing the jury. If Carl attempts to make these statements anyway, he risks a mistrial, which means he has to start over with with a new jury. In some jurisdictions, Carl may, however, be permitted to make this argument during the sentencing phase, where the court can properly consider the societal effects of whatever punishment it imposes. At this point, though, it's obviously a little late for Carl, as it presumes he has been convicted.