Prosecutors can be sued——Malicious prosecution
Despite knowing and reckless false statements or conclusory assertions of law in some of the answers above, and possible public misconceptions: There are grounds for one to sue prosecutors for prosecutorial misconduct, it is called malicious prosecution, which is rooted in part in the U.S. Constitutions Fourth Amendment's which, as relevant herein, provides that
"The right of the people to be secure in their persons […] against unreasonable […] seizures, shall not be violated[.]"
It is well-settled, that it is not merely a prohibition on the government, but, in fact, “the Fourth Amendment gives "each person ... the right to be secure against unreasonable […] seizures in his own person[.]" Minnesota v. Carter, 525 U.S. 83, 92, 119 S.Ct. 469, 142 L.Ed.2d 373 (1998) (Scalia, J., concurring)”". Byrd v. United States, 138 S. Ct. 1518, 1531 (2018)
In fact, the cause of action for malicious prosecution also existed based on the common law. Thompson v. Clark, 142 S. Ct. 1332, 1342-43 (2022) ("Thompson")
"American courts described the elements of the malicious prosecution tort as follows: (i) the suit or proceeding was "instituted without any probable cause"; (ii) the "motive in instituting" the suit "was malicious," which was often defined in this context as without probable cause and for a purpose other than bringing the defendant to justice;" and (iii) the prosecution "terminated in the acquittal or discharge of the accused." Thompson, supra, 1338 (2022)
“In accord with the elements of the malicious prosecution tort, a Fourth Amendment claim under § 1983 for malicious prosecution requires […] the plaintiff need only show that the criminal prosecution ended without a conviction.” Thompson v. Clark, 142 S. Ct. 1332, 1341 (2022)
However, "[a] comparison of the elements of the malicious-prosecution tort with the elements of a Fourth Amendment unreasonable-seizure claim shows that there is no overlap. That is, a plaintiff suing for unreasonable seizure need not prove any of the elements of common-law malicious prosecution, and a plaintiff suing for common-law malicious prosecution need not prove any of the elements required to establish an unreasonable seizure." (Thompson, supra, at p. 1342)" (bold type added)
Lack of sanity defense—the legal capacity of a substance addict
As common sense dictates: A person that loses control under the mounting psychological (or even physiological) pressure of drug addiction may lack ability to be deemed to have legal capacity for his actions to be rendered moral value absent which such actions are amoral, and their criminal condemnation are immoral, and potentially criminal.
"Is the problem materially different if the failure of the judge properly to exercise his judgment stems from the influence of illegal drugs rather than the influence of illegal money? We think not. In both cases, the litigant is deprived of the untainted judgment to which he is entitled by our Constitution. In this respect, we agree with our dissenting colleague that "corruption (a species of bias) and incapacity are cut from the same cloth . . .," but we do note an important difference: a corrupt judge has a choice; by definition, an addict driven by compulsion does not. An addict is an addict 24 hours a day, seven days a week." Summerlin v. Stewart, 267 F.3d 926, 956 (9th Cir. 2001) (bold type added)
As said above, common sense of an ordinary, reasonable person would lack the requisite belief that it was more likely than not that a person under the psychological (and/or physiological effects) of substance addiction is acting in their own free agency as a sane person.
And that is a problem. Because "in dealing with probable cause, . . . as the very name implies, we deal with probabilities. These are not technical; they are the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.' Id., at 175. Our observation in United States v. Cortez, 449 U.S. 411, 418 (1981)” Illinois v. Gates (1983) 462 U.S. 213, 231) (bold type added)
Even a reasonable and prudent man would not believe it was more likely than not that the son's judgement was clear of irresistible influence to permit him to act freely which would not permit such ordinary person to believe a crime, with the underlying moral value of a sinful mind, existed let alone a "legal technician" like a prosecutor.
Although, the primary duty to identify a potential defense of insanity is imposed on counsel, since counsel is obligated to act any time there are "sufficient indicia of incompetence to give objectively reasonable counsel reason to doubt the defendant's competency[;]" (Stanley, 633 F.3d at 862 (9th Cir. 2011) (italics added) and "[s]ince an objection to the [presumption or conclusory assertion that the son was sane at the time of the commission of prosecuted act or acts] would have been adjudicated outside the presence of the jury, there could be no satisfactory tactical reason for not making a potentially meritorious objection" (People v. Pope, 23 Cal.3d 412 (1979)) not only before the never-happened jury trial, but even before "taking" the "deal", a prosecutor must also cease prosecution (see above, malicious prosecution and false imprisonment torts) and throw the towel in no matter how much it hurts their little ego, and concerns their mom's and pop's dream to see their one and only become a state congressman/congresswoman etc.
Further, the judges themselves must also raise the question of sanity should they notice it, and once again, no half-prudent and half-reasonable person would deem a substance user with a lengthy history of such facts as outlined above (continuously, and repeatedly demanding money for drugs) and admittedly (by the "victim") that the amoral acts to the mother's detriment occurred during the time when "[the accused] needed [the money for the substance] so badly that he just took it from [the mother "victim"], pushing her around a bit but not causing any serious injury" not have been in possession of legal capacity at the time of the amoral acts.
Conclusion
In a half-decent society the dire violation of the Due Process of the law ((U.S. Const. Amndt. V. and XIV.), to the effective assistance of counsel (U.S. Const. Amndt. VI.) and to be free of unreasonable seizure to be ordered before the court and imprisoned (U.S. Const. Amndt. IV.) would be mercilessly retaliated on in the legal process, the son acquitted, sent to aversion and treatment, and be ordered to be paid damages to under § 1983 for malicious prosecution and false imprisonment without the due process of law.
You can; however, rest assured you will not find a lawyer that you don't pay out of pocket to even take the case——just look at some of the answers even the most benign, and well-intended——unless it is close family including mothers, fathers, children, siblings or spouses. Even when you will manage to get a lawyer at your own cost, the case will be preempted because should a lawyer stir up the pot too hard, you can rest assured the otherwise doing-nothing-but-covering-up State Bar of California (see "State Bar doesn’t police attorneys or itself closely enough, state audit finds", SF Chronicle) will step out of its shadows to reprimand, disbar or otherwise discipline the lawyer to step back in line, and keep it light and fun which will almost certainly never escalate to such a point as attorneys know this very well before hand so they will not even get to it.
Lesson to be learned?
If you have a problem with your family member maybe don't try to use the most dire measures to call in the police state because they will act as a police state does. Civil action would have been more than sufficient to get a restraining order and allow the child back in the house on your terms, and maybe thereby compel them to seek or accept help to treat the addiction after you screwed up parenting to the point they became a substance abuser and addict. (Don't forget: The only reason they are on this planet was doing at your own hands only and that sort of moral responsibility is infinite.) Now, if this is a middle class or well-off Saxon family in California you may also take this as my moral judgement. I hope the child will get the help they need, and will recover from all these scars.
Answers to comments:
@Jen: The whole point of Thompson v. Clark, 142 S. Ct. 1332, 1341 (2022) was to consolidate the requisites under the statutory cause of action with the common law one for malicious prosecution. The facts presented allow for both to be applicable; the common-law and statutory cause of action for malicious prosecution are substantially the same especially for purposes of this question and so are they treated.
@John Bollinger: “prosecutors' absolute immunity isn't exactly with that term might be taken to imply,that's not responsive to the question posed.” Incorrect. The facts provided by the parents to the police and indirectly to prosecutors provide for no reasonable person to believe probable cause existed since lack of mental competency was established clearly and convincingly hence more-likely-than-not basis indisputably did not exist for the commission of any crime charged. The due process of law would have first required that the prosecution presents evidence to rebut the established fact that the child did not, in fact, lack legal capacity. The prosecution was initiated without probable cause for a crime was committed absent a requisite mens rea, and was maintained without it. That’s how Thompson relates to these facts.
