What is the penalty for a bad-acting witness/expert? Say Alice from the defense/prosecution meets with Bob, some expert/witness, to establish some &quot;facts&quot;, and then Alice agrees to call Bob to the stand to establish those &quot;facts&quot; for the court. But when called the the stand, Bob presents the opposite statements, and completely sabotage's everything Alice was banking on. Are there any repercussions for Bob, or anything to dissuade him from doing this? Because if there are no repercussions, what's stopping Bob from going to the opposing side to accept money/a favour to do this for them? Also, just to be clear, consider the topic to not be a &quot;fact&quot;, but more so something that is highly contested/controversial. E.g. some &quot;experts&quot; may classify someone as insane, while others would classify the opposite, meaning there's no actual undisputed &quot;fact&quot; per se, and any &quot;expert&quot; is at liberty to think one side or the other. As one final example about a bad-acting witness/expert, consider the following scenario: Alice wants to establish her client was suffering some malediction. What's stopping her from calling Dr. SnakeOil (or Dr. Oz) to testify as such? Does the expert have to be established as legit by going through some interview as if he were applying to a company?
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.
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.
You can't prove a negative, so they can't be convicted of perjury for lying about whether they remember; Yes, they can. The government can convict the witness of perjury by proving that they did remember. This may be difficult, but it's not impossible. Now you may say that we can't ever prove with certainty what a person did or didn't remember. But the legal standard isn't certainty, it's beyond a reasonable doubt. So a jury is allowed to draw a reasonable inference about whether they remembered, based on evidence of their outward behavior and other circumstances. As an extreme example, suppose Alice was overheard chatting freely about topic X an hour before the trial, but when asked about topic X on the stand, said she didn't remember. When presented with evidence of her earlier conversation, a jury could reasonably infer that she was lying about not remembering. Is it possible that she truly had a memory lapse in the intervening hour? Sure, anything is possible. Is it reasonable to believe that she did? Probably not. The US Department of Justice's Criminal Resource Manual has this to say on the subject: Witnesses who claim not to remember, rather than deny a fact, may be prosecuted for perjury. However, the government must prove both that the witness at one time knew the fact and that the witness must have remembered it at the time he or she testified. United States v. Chen, 933 F.2d 793, 795 (9th Cir. 1991). If the dates of the transaction and testimony are sufficiently close, memory may be inferred. Instances in which the witness remembered other events that occurred at the same time or earlier than the event in question, or mentioned the event either immediately before or after his testimony, would be probative of the witness's memory at the time of the testimony. The two witness rule does not apply to prosecutions based on false memory lapses, and circumstantial evidence is sufficient, since there is no direct evidence possible concerning what the defendant actually believed. Gebhard v. United States, 422 F.2d 281, 287 (9th Cir. 1970). There's a similar issue in all laws that deal with a person's knowledge or intent. Suppose Alice hits Bob with a stick and he dies. To convict Alice of murder, it must be proved that by hitting Bob, she intended to kill him. Can we ever really know what was in her heart? Maybe not, but if there is evidence that shortly beforehand, she told someone that she was going to kill Bob, it would be a reasonable inference that this was her intention.
An "inquisitorial" system is one where the Judge or Magistrate actively questions the accused and witnesses to attempt to determine the facts. The Judge may also determine, at least in part, what witnesses to call in what order. An "adversarial" system is one in which each side presents its case, and the judge acts as an umpire deciding on procedure, and possibly makes the final ruling (or directs a jury to do so) but is not actively involved in questioning witnesses or deciding what witnesses to call. I don't see anything which would prevent a common-law jurisdiction from establishing an "inquisitorial" system by statute except longstanding tradition, but as far as i know no such jurisdiction has ever had such a system in place for dealing with criminal matters. The informal procedures in some small claims courts do have judges more actively involved than in other courts. I think this is also true in some family courts as well. I think I have heard of some civil-law jurisdictions which use something like an adversary system, but i am not sure of that. Certainly a civil-law country could pass a law setting up such a system if it chose to.
The potential problem is if there is a form which you had to sign which says "I am a US citizen", and you signed the form (who reads the fine print, anyhow?). Unfortunately, that statement is false, and there are consequences for making a false statement. However, that law penalizes false statements with the intent to deceive, not mistaken statements. Nevertheless, this is a matter that a professional really needs to deal with. If there was no form and they didn't verbally ask you to assert that you are a citizen, then there is less of a problem (for you), but still one needs to be extremely cautious in dealing with the court. [Addendum] It is highly likely that the form contained wording like "swear" or "certify" and mentions "perjury", so the error would be in the ballpark of perjury. Perjury is making "a false statement under oath or swears to the truth of a false statement previously made and the statement is required or authorized by law to be made under oath". Aggravated perjury is perjury which "is made during or in connection with an official proceeding and is material". The term "material" means "matters; is not inconsequential". The consequence of a non-citizen improperly serving on a jury is that a mistrial has occurred, which is not inconsequential. Aggravated felony is a third degree felony. The penal code says that An individual adjudged guilty of a felony of the third degree shall be punished by imprisonment in the Texas Department of Criminal Justice for any term of not more than 10 years or less than 2 years. (b) In addition to imprisonment, an individual adjudged guilty of a felony of the third degree may be punished by a fine not to exceed $10,000. I must emphasize that an essential element is "intent to deceive and with knowledge of the statement's meaning", an element that cannot be present if there is no awareness of such a statement. Thus an innocent mistake could be legally excused. When you become aware that a statement made under oath was false (assuming such a statement was made), then in maintaining the falsehood, that would be intentional deceit. This is why it is necessary to consult with a lawyer. On the Houston form, you would have to check the "are a US citizen" box. The Fort Bend county form has you certify and sign on the front page: it does not require you to certify that you are a US citizen, only to certify (and sign) if you are not – so if you failed to read the back side, that isn't a literally false statement. I can't locate an online form for Tarrant county, so dunno if that out is available.
The defence sees the prosecution evidence; witnesses don’t From context, it appears that Ms. DeCoutere was a prosecution witness, not the defendant. As such, she would not be privy to the evidence that either the prosecution or defence had or intended to present. No doubt both the prosecution and the defence would have known about the photograph and, I would imagine, it was introduced by the defence precisely because it contradicted the witness’ testimony. Further, revealing such evidence to her by either side would be misconduct - witnesses are supposed to recount the facts as they recall them without prompting or aide memoirs (police are an exception - they are allowed to refer to their own notebooks).
If Bob acknowledges how he has altered the evidence at the time he submits it, there shouldn't be any issues with it turning into falsification, which generally only becomes a problem when it's done with an intent to mislead the court. More likely, an opposing party would raise an authenticity objection, i.e, that the evidence has been altered and is therefore not trustworthy. It's probably going to be up to the judge whether to sustain that objection or not, and I'd expect the court's decision to turn in large part on how plausible it finds Bobs allegations of fraud and retaliation. I'd also expect that the Court would be less concerned with the pitch alteration than the redaction of portions of the recording. If we don't know what Bob is saying, it makes it hard to understand the full context of the conversation. Of course, all of this assumes that Bob hasn't already been forced to turn over the original recordings to Company, which he will be. The parties have a right to each other's evidence, and they are required to identify their witnesses to each other. The moment Company knows about the recording, it is going to submit a discovery request demanding a copy, and Bob will be obligated to comply. If Bob objects that doing so would expose the representatives to retaliation, I would expect the court to warn Company against tampering with witnesses and then order Bob to comply with his discovery obligations.
There is a big difference between knowing something and proving it. A lawyer who knows a client is guilty can take steps to prevent the state from proving guilt. (E.g., motion to exclude evidence, cross examining witnesses.) The belief that a client has committed a crime does not necessarily mean one knows what specific crime was committed. Is a killing Murder 1, Murder 2, or manslaughter? There are defenses even when an act may be a crime. E.g., self defense, insanity, justifiable. Lawyers are not permitted to assist in perjury. E.g., allow the client to testify to something he knows is false.