Are you required to act to preserve evidence that will otherwise be destroyed? Deliberate destruction of evidence is a crime in most jurisdictions. However, consider the following scenarios: Log files that could be used as evidence are periodically deleted unless you act. On the third incorrect password entry data is automatically erased, and you witnessed the police about to enter the third wrong password. You set up a dead man's switch that will incinerate your personal papers if not reset. You are arrested and asked for the papers, but decline to produce them. The police believe you attacked someone with knife, and your fingerprints will be on it. You wait until the knife has rusted and the fingerprints are unrecoverable before revealing its location. What are the legal consequences of not acting to preserve evidence in these cases?
I will assume that your question pertains to the United States. In other jurisdictions, different rules could apply. Context matters. The usual penalty for spoliation of evidence (the technical term for what you describe) in a civil case is a judicial determination or jury instruction that the evidence destroyed would have established the relevant part of the other side's case had it not been destroyed. In all of these cases, your failure to take affirmative action to preserve the evidence once you knew that there was a bona fide likelihood that you would be sued could be held against you by making an adverse determination that the evidence would have been unfavorable to you and possibly also money sanctions. You could not be held in contempt of court for this if these events happened before a case was commenced. In a criminal case, where you are a defendant, you have an absolute right to not incriminate yourself and do not have to take affirmative action to preserve evidence, although this right is limited to criminal cases and your failure to preserve evidence can still be held against you in a civil case. Certainly, in situation 4 you are a potential criminal defendant, so the 5th Amendment protection would apply. In situations 1 and 2, where the precautions were not put in place to facilitate a crime, the 5th Amendment would protect you if you were a potential criminal defendant, but suppose that you are a bystander like a third party ISP representative. If you were a third party, at a minimum you would have to be put on notice of the police need for the evidence, would probably have had to have had the police ask you for the evidence, and of course, would have to be aware that the destruction was imminent and have the power to prevent that destruction. If all those conditions were present, you might be guilty of obstruction of justice (there are precedents for inaction knowing of the consequences in the fact of a police question amounting to obstruction of justice). In situation 3, this kind of action pretty much amounts to being an accessory to some crime before the fact (unless someone was successfully deceived by a very elaborate story) and would likely make anyone involved part of a conspiracy to commit the crime that the destruction of the papers would facilitate. While the papers themselves might have been evidence of a crime or civil wrong, the destruction of the papers might itself be considered part of the crime, regardless of what could be established regarding the actual content of the papers.
This is a good question, although it discusses crimes. This answer generalizes the question by giving a response for civil violations. In the united-states, where federal civil-procedure is followed and provided the tape isn't solely for impeachment purposes (i.e. it also documents other elements), there are certain disclosures required at the beginning of discovery governed by Rule 26(a)(1)(A)(ii). If a party withholds one of these disclosures, under Rule 37(c)(1), the court is able to take a number of actions, including throwing the evidence out. This could, of course, result in the withholder's conviction. Yet, if the court does not go to that extreme, it may impose the sanctions in Rule 37(b). So the withholder's attorney might try to make a case that the evidence is, indeed, solely for impeachment purposes.
Intent would greatly factor into the case. As mentioned, possession of child pornography is illegal. There was a case, where a man had inadvertently downloaded such images. In the case, it was shown that there was sufficient evidence that it was accidental and without his knowledge. Presumably, if you by happenstance created an identical code through encryption/compiling, there would be a lack of evidence of intent or evidence of your intended use. For example, your stored password manager file happens to store data identical to an illegal image. The password manager output is provable and repeatable to show that it was simply circumstantial. If you have hundreds of such outputs that all "just happen to be illicit images" you would probably fall on the wrong side of reasonable doubt. As to whether you can keep the data, the programmers for the password manager would probably update their system to modify the output to avoid bad press. The general idea is that the "illegal number" is so incredibly specific that accidental cases are very unlikely to occur, and if it did, that there would be forensic evidence indicating intent and use.
It doesn't really require anything beyond your say-so that it is what you say it is; that would be enough to satisfy the requirement for authentication. From there though, as with any evidence, it's going to be up to a jury to decide how much weight to give the evidence. So the more you can show them to prove that the record is real -- and to knock down any questions the opposing party will raise -- the more likely they are to believe it. So if you just bring a printout that looks like it could easily have been forged, the jury may be thinking about that. If you can bring in a data forensics expert to say the document couldn't have been faked, that's probably going to help. Addendum: As a practical matter, I wouldn't expect this to be much of an issue. Unless you're dealing with a savvy opposing party, the authenticity of e-mails seems to be generally assumed. Courts (1) generally assume that parties aren't perpetrating frauds; and (2) are generally run by judges with little to no technical savvy, who don't realize that one could forge an e-mail, let alone all the different ways it could be done. I've personally entered countless e-mail printouts without them being questioned, even though either party could have just gone down into the e-mail thread and changed what the other side had said earlier in the conversation. To avoid the issue, though, it might be that sending the e-mail to a Gmail account would elimimate the question.
Theoretically, yes it can, but it is highly fact specific The Court of Appeal explicitly answered this question in the case of R v Bown [2003] EWCA Crim 1989; [2004] 1 Cr App R 13. The Court held per Keene LJ that self-harm was capable of being a good reason within the meaning of subsection 4 of s 139 (para 20). While refraining from any abstract holding as to self-harm (which required a fact-based analysis), Keene LJ held (at para 24–5) that this would depend on evidence as to how and in what manner the bladed article was intended to be used and the time and place relating to said use. The burden of demonstrating this fell on the defence and it would require detailed evidence to be a presentable defence. In the case at bar, the absence of any evidence directly linking the possession of the knife to the tendency of the defendant to self-harm meant that there was nothing which could establish the defence to be put to the jury; a high 'degree of particularity was requisite' (para 27). NB: yes, the name of the defendant in this case is actually 'Bown', not 'Brown'—I know it looks like a typo!
Doing something to a dead body that would kill it if it were a living person is not murder, manslaughter, or any form of homicide in any country that I know of. It may be a crime to mutilate a corpse, or some similar provision. It may also be attempted murder. For example, in the US state of Oklahoma, section §21-1161.1 provides: A. It is unlawful for any person to knowingly and willfully desecrate a human corpse for any purpose of: Tampering with the evidence of a crime; Camouflaging the death of human being; Disposing of a dead body; Impeding or prohibiting the detection, investigation or prosecution of a crime; Altering, inhibiting or concealing the identification of a dead body, a crime victim, or a criminal offender; or Disrupting, prohibiting or interfering with any law enforcement agency or the Office of the State Medical Examiner in detecting, investigating, examining, determining, identifying or processing a dead body, cause of death, the scene where a dead body is found, or any forensic examination or investigation relating to a dead body or a crime. B. Upon conviction, the violator of any provision of this section shall be guilty of a felony punishable by imprisonment in the custody of the Department of Corrections for a term not more than seven (7) years, by a fine not exceeding Eight Thousand Dollars ($8,000.00), or by both such fine and imprisonment. In addition, if the person thought that the dead body was a living person, and tried to kill that person. There may be a charge of attempted murder on which a conviction might be possible. See &quot;attempted murder&quot; of a dead man? for details. In general, if property (such as a cell phone) has been stole from a person, that person my reclaim such property, and doing so is not theft. However, a person is not in most jurisdictions permitted to enter someone else's property, to break and enter, or to assault a suspected thief in order to recover property. A person who actually observes a theft (or other serious crime) is in many jurisdictions allowed to pursue the thief/criminal and use reasonable non-deadly force to stop and detain the thief pending the arrival of law enforcement, who should be promptly summoned. The details vary widely from place to place. The use of deadly force, such as a gun, is generally not permitted, except in proper self-defense, but again the details vary widely.
The common law adversarial system is just that: the prosecution must prove its case beyond reasonable doubt. The defense is not obliged to call evidence at all. They are allowed to though: they will do it merely if they feel that the prosecution evidence needs rebuttal — in order to discredit the evidence or, at least, raise that &quot;reasonable doubt&quot;.
If that which you describe in your comment ( Facebook post as only basis for warrantless search) is, and can be shown, to be the only basis for the search, and there was no evidence of a crime in plain view when they arrived.....then yes, it is likely the search and all evidence acquired from the search would be excludable. As to whether the individual could still be prosecuted, that depends if a case could be built independent of the evidence collected during the search.