Can I be charged for murder if I throw peanuts at someone who has a severe peanut allergy and they die as a result of that? Assuming I already knew that they had a peanut allergy, and my intention was to hurt them, but not necessarily to kill them.
You don't specify a jurisdiction but taking the US as an example, yes you could be charged with 2nd Degree Murder - you intended to harm them but not specifically to kill them: A second situation that constitutes second-degree murder is where the perpetrator intends only to cause serious bodily harm but knows that death could result from the act. For example, in the situation above, instead of shooting Bill, Adam grabs a shovel and whacks Bill in the head with all his strength. While Adam didn't specifically intend to kill Bill when he hit him, he did intend to strike him with the shovel knowing that such a blow to the head carried with it a distinct possibility of death. Adam killing Bill in this way would be classified as murder in the second degree. In English law you'd be facing charges for Voluntary Manslaughter
There are many cases where it is quite obvious that A has illegally killed B, but where it is much less obvious whether this was first degree murder, second degree murder, or manslaughter. The usual approach is to charge A with all three, and then convict for the highest that the jury agrees with (for example, the jury might agree that it was at least second degree murder, but not agree that it was first degree murder beyond reasonable ground). A prosecutor who wants a first degree murder conviction might charge with first degree murder only, hoping that the jury will agree with the charge rather than letting a proven killer go free. This may fatally backfire. If a proven killer is only charged with first degree murder, and there is insufficient evidence for first degree murder, then yes, with a responsible jury that killer will go free. If the only charge requires proof of premeditation, and there is no proof, then that charge will not succeed.
The double jeopardy clause would prevent you from being retried by the government that tried you for murder (probably a U.S. state). But, you could be tried for fraud and obstruction of justice at the state level, and you could be tried for murder if an appropriate federal offense were located, at the federal level. Often conspiracy to deprive someone of their civil rights is used as a federal offense when there is a state level acquittal, and it isn't impossible to imagine that happening in this case as the victim had a right to the protection of the laws, and the state had a right to enforce the criminal laws, which was deprived in a manner that could be called "under color of state law.'
The main source of liability would be "for injuries caused by the act 'of things that he has under his guard'" (this article). As stated in Art. 1383. of the 1804 Civil Code, "Everyone is liable for the injury he has caused not only by his act, but also by his negligence or imprudence". Then the question is whether the teacher was negligent in allowing a poisoning to happen. It is much more difficult to judge French standards, since court rulings do not generally create legal principles. To take two extremes, suppose on the one hand that a teacher were to store a bottle of sulfuric acid on the table where anyone could take it. Knowing that some rapscallion might take the bottle and prank someone with it, the teacher might have neglected her duty as a teacher to safeguard students. However, if it is safely locked up and yet someone manages to get into the locker (e.g. they have a safe-cracking device that nobody expects a student to have access to), then she probably would not be liable. The difference comes from whether there is fault in the teacher's choices of action, that is, is that choice something that a reasonable person would know is wrong. It's not clear from the description how Bob got the substance: finding a means of preventing students from accessing dangerous materials should be the main goal, and probably does not require stopping experimentation. But facts about the school might imply that the risk is not practically controllable (e.g. no locks on the chemical cabinet).
It's happened before in real life. Here is a 1994 article describing an Illinois criminal trial where defense counsel pulled the old switcheroo and sat a different person with him at the defense table instead of the defendant. The defendant, instead, sat somewhere else in the courtroom. After a witness misidentified the perp as the person at the defense table (not the defendant), the judge directed a not-guilty verdict to settle the case but sanctioned the defense attorney instead. The appellate and state supreme courts upheld the sanction (by a one-vote margin in both cases) but dissenting opinions noted counsel and defendant technically broke no rules. From the article: The dissent said Mr. Sotomayor's intent was only to show the unreliability of the prosecution's witness. Moreover, seating a client at counsel's table is customary but not required. Nor is a lawyer obliged [...] to help a witness make an identification. Also, here is a similar but not duplicate question.
In the US, it depends on the jurisdiction because each state has its own homicide statutes: but, the defining elements don't differ a lot. Drawing on Washington state law, the first question is whether you intended to kill a person (it doesn't have to be a specific person). If you did, you have committed first-degree murder. It is first-degree murder, because it requires a certain amount of advance planning to kill with a drone. It does not matter that the drone houses the gun that killed the person and a program determines when the gun fires (the "it was the drone, not me" defense gets you nowhere: otherwise, you could always claim "It wasn't me, it was my gun / knife / fist".) If instead this is a badly-designed pig-slaughtering drone, then it could be manslaughter in the first degree, if the act was reckless, or manslaughter in the second degree, if the act was with criminal negligence. To determine which it is, you look at the definitions: A person is reckless or acts recklessly when he or she knows of and disregards a substantial risk that a wrongful act may occur and his or her disregard of such substantial risk is a gross deviation from conduct that a reasonable person would exercise in the same situation. versus A person is criminally negligent or acts with criminal negligence when he or she fails to be aware of a substantial risk that a wrongful act may occur and his or her failure to be aware of such substantial risk constitutes a gross deviation from the standard of care that a reasonable person would exercise in the same situation. So it would depend on whether you decided that safeguards which would prevent shooting people were too much bother (you know there is a risk and set aside that concern), or it didn't occur to you that a flying gun might hurt a person.
It is not necessarily a crime to do this, but the gift to you and from you to Betty would be disregarded and treated as if gift directly from Alice to Betty, if the IRS knew all of the facts. A gift implies a donative intent directed at you. When there is an understanding that you are acting at Alice's direction, you aren't receiving a gift, you are acting as Alice's agent. This said, this scheme, or the alternative it seeks to prevent, has no impact on Betty, because gift taxes are imposed on the donor rather than the recipient of the gift. And, in most cases, a gift in excess of the $14,000 per person per year gift tax exemption will have only a minimal impact. This is because each person is entitled to make a combination of gifts in excess of the exemption during life and transfers to non-spouses and non-charities at death of $11,200,000 per lifetime (adjusted annually for inflation). Usually, all that is necessary if the limit is exceeded is for the donor to file form 706 (a federal gift tax return) at the same time as the donor's income tax return, and this form is very simple if the only gifts given are cash gifts. Transfers to a U.S. citizen spouse are gift and estate tax free, as are gifts to foreign and domestic charities. Spouses who file a Form 709 in a year may treat gifts given by one spouse as actually given half by each spouse. If someone dies not having used their entire $11,200,000 (adjusted for inflation) lifetime exemption, their surviving spouse, if any, inherits that unused portion and can use it at their death in addition to their own lifetime exemption. So, Alice and Betty are trying to evade a tax law that is easy and trouble free to comply with, and may provide future benefits by documenting the intent of the parties with respect to a large gift (so that someone doesn't later try to characterize it as a loan or contribution to a trust estate, for example). While it isn't a crime, it is ill advised and won't benefit them materially in the end.
Theoretically you could, but that's highly unlikely if what you say is all there is to it. The prosecutor would have to have good evidence that you had a criminal intent, for example intended to make off with the goods. You could even attach a note of explanation to overcome any suspicion of criminal intent.