Why are there distinct burdens of proof in civil and criminal cases? In a criminal case, in all common law jurisdictions that I know of, an accusation must be proven to a high level which is commonly stated as being "beyond reasonable doubt", whereas in a civil case the burden of proof of the accusation is typically lower, expressed as something like "preponderance of evidence" or perhaps "more likely than not". Is there any explanation in the legal literature of what justifies having a distinction in burden of proof?
Because in a civil case you have two equally involved sides. If I claim you damaged my car which cost $10,000 to repair, it's not only that you lose $10,000 if you lose the case, but I lose $10,000 if you win the case. Therefore the burden of proof should be equal in both directions. Assume a kid at an expensive boarding school is accused of causing $10,000 damage to the headmaster's car, and instead of suing for damages, the headmaster took the $10,000 out of the kid's school fees and tells the parents that the kid will be thrown out if they don't pay another $10,000. We have the exact same argument, but now the headmaster would be in court and accused. If the burden of proof was "proven beyond reasonable doubt", in the first case the parents would have to pay if it was proven beyond reasonable doubt that the kid was responsible; in the second case they would only get their money back if it was proven beyond reasonable doubt that the kid was not responsible.
The standard of proof for a criminal conviction is the same. So they would similarly need to prove beyond a reasonable doubt to convict the foreign national of a crime. But deportation is not a criminal proceeding, and has a different standard of proof. (In deportation you also don't have criminal defendant rights like right to an attorney if you can't afford one.) I believe the standard is "clear and convincing evidence".
(My expectation is that the proof has to be replicated and the conviction cannot be introduced as evidence). Your expectation is incorrect. The name of the legal doctrine that allows a criminal judgment to have this effect in a civil case is called "collateral estoppel" which is also sometimes called "issue preclusion". See, e.g., A-1 Auto Repair &amp; Detail, Inc. v. Bilunas-Hardy, 93 P.3d 598, 600 (Colo. App. 2004) ("Hardy contends Colorado law does not allow courts to apply collateral estoppel, now commonly known as the doctrine of issue preclusion, when the first adjudication is criminal and the subsequent litigation is civil. We disagree.") Similarly, a case out of California stated: To preclude a civil litigant from relitigating an issue previously found against him in a criminal prosecution is less severe than to preclude him from relitigating such an issue in successive civil trials, for there are rigorous safeguards against unjust conviction, including the requirements of proof beyond a reasonable doubt and of a unanimous verdict, the right to counsel, and a record paid for by the state on appeal. Stability of judgments and expeditious trials are served and no injustice done, when criminal defendants are estopped from relitigating issues determined in conformity with these safeguards. Teitelbaum Furs, Inc. v. Dominion Ins. Co., 58 Cal.2d 601, 606, 25 Cal.Rptr. 559, 375 P.2d 439, 441 (1962) (citations omitted). To the best of my knowledge, this is the rule in every U.S. jurisdiction (with the possible exceptions of Puerto Rico and Louisiana which are not common law jurisdictions). It is also the historical rule in British common law, although I don't know if this continues to be the case in non-U.S. jurisdictions. Procedurally, the determination that collateral estoppel applies would usually be made on a motion for summary judgment, or in the preparation of jury instructions which state that liability has been established and that the jury is to limit itself to determining causation and damages, rather than as an evidentiary matter. I've used this doctrine once or twice. For example, I used it in a case where someone fraudulently sold ditch company shares worth several hundred thousand dollars (in Colorado, water is gold) that he didn't own (a transaction that could not be unwound because the buyer was a bona fide purchaser for value and the seller had apparent authority as a trustee of a trust owning the shares even though he didn't have the actual authority to sell them under the trust) and then spent the money he received before he was discovered (if I recall correctly, for gambling debts). He was convicted criminally and then my client, the victim, sued for money damages including statutory treble damages for civil theft and attorney's fees based upon collateral estoppel and an affidavit as to damages in a motion for summary judgment. From a practical perspective the four main difficulties are that (1) people convicted of crimes often lack the income or assets to pay judgments, (2) there are double recovery issues involved in reconciling restitution awards in a criminal case (where the measure of damages is narrower) and damage awards in a civil case (where the measure of damages is broader), (3) there are priority issues involved in reconciling criminal awards for fines, restitution and costs, in each case with civil awards for damages, and (4) if the defendant declares bankruptcy, the non-dischargeability of the civil judgment must be affirmatively raised and proved (often this is elementary but there are strict time limits) in the bankruptcy proceeding. Tactically, it is often better to sue first, collect what you can, and to bring a criminal complaint only when it turns out that the perpetrator is judgment-proof.
The defence in a criminal case has no obligation to inform the prosecution of anything. The onus is on the prosecution to provide the evidence to convict and the defence doesn't have to and indeed shouldn't help them do it. The defence can and probably would use conflicting statements by a prosecution witness to discredit that witness in the eyes of the jury. These do not have to be material to the case: just showing the witness is inconsistent in general is helpful.
Prejudice and bias goes to credibility The trier of fact has to decide how much weight to give each piece of evidence including witness testimony. A clearly prejudiced or biased witness will, all else being equal, deserve less weight than a more unbiased or less prejudiced witness. Or, at least, one who is less obviously biased and prejudiced - because everyone is biased and prejudiced. A witness who clearly and unequivocally declared their bias and prejudice probably deserves more credit than one who reveals it unwillingly during examination. The witnesses you use are the people who were there - you don’t get to choose their character.
The main rules in a civil case are the rules of evidence, the rules of civil procedure, and a set of largely unwritten rules governing issues such as the order in which matters are presented in a trial and courtroom conduct. Basically, the rules of evidence are really a subset of a larger set of written and unwritten rules about courtroom conduct the unwritten parts of which are assumed to be known by people using them. Robert's Rules of Order do not apply to courtroom proceedings. The judge also has the "direct contempt" power to summarily punish disrespectful conduct in the courtroom without a trial, with fines or incarceration, even if it wouldn't be a crime outside the courtroom. But what if a party to the proceedings who does not "have the floor" wishes to do things like the following: Obtain a restatement (perhaps because it was unintelligible, or perhaps as a ploy for emphasis) of something uttered by another. If you are a party asking a question (or more likely an attorney for a party asking a question on behalf of a party) it is not improper to say, "I'm sorry, I couldn't hear you." It is also not generally improper for a non-questioning party to interject and state that they can't hear a witness to a judge. Obtain clarification of a statement. This can be done by a party only when it is the party's turn to cross-examine or redirect as the case may be. A judge can ask for clarification, but a party cannot do so when it is not their turn. Determine or clarify the purpose of an ongoing statement or line of questioning Generally the party not asking a question objects and the court asks the party asking the question to clarify the reason. Sometimes, in a jury trial, the party asked to clarify will say "may we approach the bench" and a private discussion will be held between counsel for both sides and the judge regarding an ongoing issue. Determine whether the judge will allow something later in the proceedings. (E.g., "At some point I hope to speak to point X. May I do that now? Or will I be afforded that opportunity at some later point before the conclusion of this hearing?") Lawyers are expected to know this for the most part without having to ask. Also, usually before the court starts to take evidence, and at breaks, the judge will ask "are there any preliminary matters that need to be addressed?" or "are there any procedural matters that need to be addressed?" and questions such as this can be raised at that time.
Acquittals in criminal jury trials cannot be appealed (at least in a way that affects the outcome, Colorado and a few other states allow criminal appeals by the prosecution solely for the purposes of clarifying the law prospectively). Interlocutory appeals (i.e. appeals before the case is over) by the prosecution are allowed for pre-trial rulings (e.g. suppression of evidence rulings in a pre-trial hearing), in criminal cases, but not for evidentiary rulings made in the midst of a jury trial (which is when jeopardy attaches for the purposes of the double jeopardy rule, which is what prevents acquittals from being retried). An error in a ruling on an admission or rejection of evidence at trial may be appealed by a convicted defendant if the alleged misapplication of the evidence rule was an abuse of discretion by the judge, and was not &quot;harmless error&quot; (i.e. if as part of all errors made in the case there is a reasonable probability that it changed the outcome that the jury reached).
Bad people are quite uncommon Most people behave in good faith most of the time - don't tie yourself in knots over the very few people who would be unscrupulous enough to try to do this. Burden of proof The person who makes the allegation has the burden of proof on the balance of probabilities. So the person who claims they didn't receive it has to prove that. If there are two equally credible witnesses, one saying they packed and posted the thing and one saying the thing was not packed then the burden has not been met. If the person who packed it has a photo of it packed and addressed then the other person has definitely not met their burden of proof. Insurance Insure it against loss or damage in transit. Then you can just replace it and claim on your insurance.