This scenario you describe pushes very hard on the distinction between moral guilt and legal guilt, at least in American law.
Generally speaking under American law, if Knox and Sollecito intended for Guede to commit a serious crime against Kercher (such as rape or robbery), and Guede killed Kercher in the process, then Knox and Sollecito would be guilty of murder.
So, from your point of view:
P(Knox guilty) = .9
P(prosecutor correct) = .85
Basically yes, if by “prosecutor correct” you mean the prosecutor is correct that Knox and Sollecito physically participated in the murder. The prosecutor’s scenario contained a lot of details; it’s very likely that some of those details are wrong.
Also, I think that if P(defendant is guilty) less P(prosecutor’s theory is correct) is in the range of .05, that is strong evidence that the prosecutor is utterly incompetent
I disagree, depending on how you define “incompetent.” Let’s suppose you are the prosecutor—you are confident that Knox and Sollecito were involved in the murder but you don’t know exactly what happened. The police have brought you evidence suggesting that Knox stabbed Kercher. You know that in order to convict, you need to give the jury a plausible scenario for what happened. What choice do you have but to make your best guess and go with it?
Perhaps a better argument can be made that the prosecutors were unethical for advancing their speculations about sex games and such to the jury. It would be interesting to see a translation of the transcript of the prosecutor’s opening and closing arguments.
Generally speaking under American law, if Knox and Sollecito intended for Guede to commit a serious crime against Kercher (such as rape or robbery), and Guede killed Kercher in the process, then Knox and Sollecito would be guilty of murder.
Regardless of what Knox and Sollecito intended, they are guilty of none of Guede’s crimes unless they acted to participate in some way. But I agree that if Knox had committed conspiracy to rape (or rob, or whatever) Kercher with Guede, then she would be guilty of any murder Guede committed in furtherance or in consequence of that conspiracy. I’ll agree to a similar statement about aiding and abetting, but I don’t remember the technical language. (And all of this is American law, which is of limited relevance in Italy).
I disagree, depending on how you define “incompetent.” Let’s suppose you are the prosecutor—you are confident that Knox and Sollecito were involved in the murder but you don’t know exactly what happened. The police have brought you evidence suggesting that Knox stabbed Kercher. You know that in order to convict, you need to give the jury a plausible scenario for what happened. What choice do you have but to make your best guess and go with it?
A prosecutor’s theory is correct if it includes all the true, morally relevant details. Further, it contains no false, morally relevant details. Compare the a prosecutor saying:
(1) “The defendant shot the victim with a .44 caliber gun, but I don’t know the model of the gun.”
(2) “The defendant shot the victim, but I don’t know the caliber of the gun”
Assuming the statements are true descriptions of what actually occurred, the prosecutor saying (1) is correct and the prosecutor saying (2) is pushing the envelope. Further, a prosecutor who says, “The defendant shot the victim, and the killing was planned ahead of time,” when the defendant actually decided to kill during the meeting is incorrect.
As the last example shows, a defendant can be guilt of the crime charged. But I assert that prosecutors assert stories that contain morally relevant that are inconsistent with what actually happened far less than 5% of the time. And when inconsistencies happen, it suggests that the prosecutor is wrong on other morally relevant details.
The prosecutor’s scenario contained a lot of details; it’s very likely that some of those details are wrong.
From what I understand of the prosecutor’s theory of the case, it contained many additional morally relevant details beyond simply Knox and Sollecito’s physical involvement in Kercher’s murder.
P(Knox guilty) = .9
P(prosecutor correct) = .85
For the reasons I just discussed, your probability distribution seems inconsistent with the evidence. Specifically, you rescue Knox and Sollecito’s guilty from possible errors by the prosecutor by proposing a theory that even you think has only a 5% chance of being true.
Regardless of what Knox and Sollecito intended, they are guilty of none of Guede’s crimes unless they acted to participate in some way. But I agree that if Knox had committed conspiracy to rape (or rob, or whatever) Kercher with Guede, then she would be guilty of any murder Guede committed in furtherance or in consequence of that conspiracy. I’ll agree to a similar statement about aiding and abetting, but I don’t remember the technical language.
Agree.
A prosecutor’s theory is correct if it includes all the true, morally relevant details. Further, it contains no false, morally relevant details. Compare the a prosecutor saying:
I’m not sure what your point is here. Are we arguing about whether the prosecutor is competent? About whether he is unethical?
Do you agree that as a practical matter, in order to have a good chance of securing a conviction, a prosecutor needs to present a coherent narrative to the jury?
Specifically, you rescue Knox and Sollecito’s guilty from possible errors by the prosecutor by proposing a theory that even you think has only a 5% chance of being true.
I don’t understand this sentence. I’m reluctant to guess at what you mean, but please keep in mind that “prosecutor correct” can be taken different ways. Does it mean simply that he is correct about physical involvement; or does it mean that his entire narrative is substantially correct?
I don’t understand this sentence. I’m reluctant to guess at what you mean, but please keep in mind that “prosecutor correct” can be taken different ways. Does it mean simply that he is correct about physical involvement; or does it mean that his entire narrative is substantially correct?
My previous post was trying to define what I meant by correctness for the purpose of the probability analysis I did. In brief, a prosecutor is correct if the theory presented to the jury contains no morally relevant facts that are contradicted by what actually occurred. (To clarify what I mean by moral relevance: Did the burglar go in the unlocked front or unlocked back door? Legally relevant, but not morally relevant).
Thus, I think the answer to your question is that the prosecutor is incorrect if the narrative does not correctly describe what actually occurred. As I noted above, the prosecutor’s incorrectness is not inconsistent with the defendant’s legal guilt. But I assert that prosecutor’s incorrectness is suggestive of legal innocence because it shows the prosecutor doesn’t know what happened.
Do you agree that as a practical matter, in order to have a good chance of securing a conviction, a prosecutor needs to present a coherent narrative to the jury?
Sure, juries like stories. That isn’t precisely a rationalist feature of juries.
In the Kercher case, the prosecutor’s case was filled with morally relevant facts (e.g. the sex cult/orgy thing) that were wildly implausible and not supported by any evidence that I’m aware of. Then, more plausible assertions (i.e. it was impossible to enter the apartment via the fire escape) were contradicted. Since I independently believe that (P(defendant guilty of charged crime) & P(prosecutor incorrect)) is small, I’m left to estimate a very small likelihood that Knox is guilty.
Thus, I think the answer to your question is that the prosecutor is incorrect if the narrative does not correctly describe what actually occurred. As I noted above, the prosecutor’s incorrectness is not inconsistent with the defendant’s legal guilt. But I assert that prosecutor’s incorrectness is suggestive of legal innocence because it shows the prosecutor doesn’t know what happened.
Fine, but you don’t get to redefine the terms I used and then use your different definition to conclude that my probability estimate doesn’t make sense. That would be a fancy way of strawmanning me.
When I basically agreed that I believe that P (prosecutor correct) is 85%, I was careful to make clear what I meant by “prosecutor correct.” Please do not pretend that I meant (or that we were discussing) something different.
It was not my intent to strawman you. I seem to have misunderstood your position. Let’s return to basics.
Let’s define “no orgy, but guilty” as the state in which Knox and Sollecito are legally guilty of Kercher’s murder, but many of the prosecutor’s asserted morally relevant facts are false. By definition:
P(guilty) = P(prosecutor correct) + P(no orgy, but guilty)
P(no orgy, but guilty) = P(prosecutor incorrect) & P(guilty) [If I understand the terminology correctly]
Since you seem to agree that the prosecutor made incorrect assertions of morally relevant facts, your value of P(prosecutor correct) is negligibly small. Why do you think that the prosecutor made the assertions? Before you say “narrative,” let me assert that many of the prosecutor’s assertions could have been replaced with “I don’t know” with limited loss of coherence to the narrative.
Why do you think that the prosecutor made the assertions?
Can you give me a specific example?
Before you say “narrative,” let me assert that many of the prosecutor’s assertions could have been replaced with “I don’t know” with limited loss of coherence to the narrative
Ok, you’ve said it. And now my answer:
Narrative. I do agree that the prosecutor could have omitted a few things and still had a somewhat coherent narrative. But if he got rid of all the speculation, what he would be left without any motive or explanation for why Knox and Sollecito acted in concert with Guede.
Why do you think that the prosecutor made the assertions?
Can you give me a specific example?
Quoting wikipedia: “[The prosecutor alleged] that the murder was part of a Satanic ritual; that it was a sex game gone wrong; or that Kercher had refused to take part in an orgy.”
Honestly, a substantial part of my doubt of Knox and Sollecito’s guilt is the utter ridiculousness of those allegations. They were not necessary to provide narrative to the jury and could easily have been omitted, since there was apparently no evidence suggesting they were true.
Further, they are the type of allegations I would expect when the prosecutor is seeking to inflame, rather than rationally presenting the evidence.
Quoting wikipedia: “[The prosecutor alleged] that the murder was part of a Satanic ritual; that it was a sex game gone wrong; or that Kercher had refused to take part in an orgy.”
Ok, to answer your question, I believe that the prosecutor made these assertions because he felt pressure to answer the question of Knox and Sollecito’s motives.
Satanic ritual? The prosecutor could have just said, “The roommates had a big fight.” In terms of evidence of guilt, there are two major problems in the “satanic ritual” theory that are not present in a more mundane theory. The satanic ritual theory proves too much, in that there is almost no evidence that could possibly be inconsistent with it. Second, the theory functions to demonize the defendants, which is not consistent with strong actual evidence of guilt.
And those theoretical arguments ignore the practical fact that there was no evidence suggesting interest in satanic ritual by either defendant, which I consider important given the general implausibility of the theory given what I know about society (There are practically no murderous satanists in real life).
The prosecutor could have just said, “The roommates had a big fight.”
Apparently he did also propose more mundane motives. Here’s the full quote from Wikipedia:
The prosecutors proposed a number of possible motives for the murder, for which they produced no evidence, including that Kercher and Knox had fallen out over issues such as the cleaning roster in their home; that the murder was part of a Satanic ritual; that it was a sex game gone wrong; or that Kercher had refused to take part in an orgy.
When you quoted Wikipedia, why did you omit the part about the cleaning roster?
Because I’m interested in why the prosecutor kept talking after he articulated that theory.
Either theory is just speculation, agreed? I mean, if it’s unethical for the prosecutor to argue that there was a satanic ritual, it’s also unethical for him to argue that it’s a dispute over who should clean the apartment. Agreed?
I’m not trying to say the prosecutor is unethical. I’m saying that outlandish claims from the prosecutor are evidence of innocence. It’s just a Big Lie
And if the prosecutor really has no idea why defendant committed a crime, that’s also evidence of innocence, right?
One could rationalize the prosecutor’s behavior by saying that lower standards apply to statements to the media than statements in court. But the reason that it’s unethical to try cases in the media is that this reduces the likelihood that the trial will be correlated with the truth. I attribute knowledge of that principle to the prosecutor, so his decision to try the case in the media suggests that the defendants are innocent.
Ok, I thought we were discussing whether the prosecutor was ethical.
We were discussing whether the prosecutor is competent.
the decision to arrest Knox is evidence of guilt.
No, it isn’t. The decision to arrest is evidence that the authorities think they have evidence of guilt. But the arrest is not independent of the underlying evidence and does not make the underlying evidence stronger.
We were discussing whether the prosecutor is competent.
Ok, then why are you bringing up the question of whether the prosecutor’s assertions are evidentiary?
The decision to arrest is evidence that the authorities think they have evidence of guilt. But the arrest is not independent of the underlying evidence and does not make the underlying evidence stronger.
Similarly, the prosecutor’s proposal that there may have been a Satanic ritual involved is not independent of the underlying (lack of) evidence of motive and does not make the underlying evidence weaker.
The prosecutor’s theory is not evidence of the same type as DNA. But it tells us something about how strong the prosecutor thinks the legally relevant evidence is.
The reference to satanic ritual and sex games is an appeal to applause lights. It is political machinations, not an empirically based search for truth. The fact that the prosecutor made that appeal, rather than sticking with a plausible story, shows that the prosecutor doesn’t think the facts support guilt or doesn’t care.
As an observer, I’m allowed to give weight to the fact that one side of a dispute doesn’t seem to be trying to determine the facts.
The prosecutor’s theory is not evidence of the same type as DNA. But it tells us something about how strong the prosecutor thinks the legally relevant evidence is.
The decision to arrest the defendant is not the same type as DNA. But it tells us something about how strong the authorities think the legally relevant evidence is.
As an observer, I’m allowed to give weight to the fact that one side of a dispute doesn’t seem to be trying to determine the facts
I would say the amount of weight depends on the extent you are relying on unsupported assertions of that side. For example, if we knew nothing at all about the case except the prosecutor saying “Trust me, I have reviewed the evidence and I am satisfied that the Defendant is guilty, it would be very important that the prosecutor is proposing a seemingly outlandish hypothesis.
This is the expertise problem. You and I do not have access to all the evidence, so we look to the experts. If anyone is an expert on the strength of the case, it is the prosecutor. And a prosecutor referencing satanic rituals and sex cults is like a psychologist referencing the “Niceness Gene” to explain some behavior. It isn’t impossibly wrong, but it strongly suggests the expert doesn’t know what he is talking about.
This is the expertise problem. You and I do not have access to all the evidence, so we look to the experts. If anyone is an expert on the strength of the case, it is the prosecutor.
So in your view, any probability assessment of Knox’s guilt which does not put a lot of weight on the prosecutor’s credibility is deeply flawed. Agreed?
No. The physical evidence does not support Knox’s guilt. But the fact is that the prosecutor and other Italian authorities are engaging in a lot of motivated cognition to support the theory of guilt even when the evidence doesn’t support it.
The motivated cognition is so blatant that it persuaded me that Knox was probably not guilty even before I looked at the evidence. I suspect that if the world were more rational, my reasoning would be less likely to provide useful insight.
No. The physical evidence does not support Knox’s guilt.
How do you know this if you do not have access to all of the evidence and therefore must “look to the experts”?
It seems to me that you and I both have access to enough of the evidence to make a decent estimate of the probability of Knox’s guilt without relying on someone who has superior access to the evidence.
My estimate of how ethical it is for a prosecutor to propose theory X about a defendant’s motive increases with how common X is, and decreases with how sensational X is. Roommates arguing over cleaning an apartment is both more common and less sensational than satanic rituals, so my estimates of how ethical it is to propose those theories differs.
Of course, maybe there’s some particularly salient threshold that both examples exceed. If so, it’s worth articulating that threshold explicitly… when it comes to propounding theories about motive, it’s not clear to me what that threshold is or ought to be.
Generally speaking under American law, if Knox and Sollecito intended for Guede to commit a serious crime against Kercher (such as rape or robbery), and Guede killed Kercher in the process, then Knox and Sollecito would be guilty of murder.
Basically yes, if by “prosecutor correct” you mean the prosecutor is correct that Knox and Sollecito physically participated in the murder. The prosecutor’s scenario contained a lot of details; it’s very likely that some of those details are wrong.
I disagree, depending on how you define “incompetent.” Let’s suppose you are the prosecutor—you are confident that Knox and Sollecito were involved in the murder but you don’t know exactly what happened. The police have brought you evidence suggesting that Knox stabbed Kercher. You know that in order to convict, you need to give the jury a plausible scenario for what happened. What choice do you have but to make your best guess and go with it?
Perhaps a better argument can be made that the prosecutors were unethical for advancing their speculations about sex games and such to the jury. It would be interesting to see a translation of the transcript of the prosecutor’s opening and closing arguments.
Regardless of what Knox and Sollecito intended, they are guilty of none of Guede’s crimes unless they acted to participate in some way. But I agree that if Knox had committed conspiracy to rape (or rob, or whatever) Kercher with Guede, then she would be guilty of any murder Guede committed in furtherance or in consequence of that conspiracy. I’ll agree to a similar statement about aiding and abetting, but I don’t remember the technical language. (And all of this is American law, which is of limited relevance in Italy).
A prosecutor’s theory is correct if it includes all the true, morally relevant details. Further, it contains no false, morally relevant details. Compare the a prosecutor saying:
(1) “The defendant shot the victim with a .44 caliber gun, but I don’t know the model of the gun.”
(2) “The defendant shot the victim, but I don’t know the caliber of the gun”
Assuming the statements are true descriptions of what actually occurred, the prosecutor saying (1) is correct and the prosecutor saying (2) is pushing the envelope. Further, a prosecutor who says, “The defendant shot the victim, and the killing was planned ahead of time,” when the defendant actually decided to kill during the meeting is incorrect.
As the last example shows, a defendant can be guilt of the crime charged. But I assert that prosecutors assert stories that contain morally relevant that are inconsistent with what actually happened far less than 5% of the time. And when inconsistencies happen, it suggests that the prosecutor is wrong on other morally relevant details.
From what I understand of the prosecutor’s theory of the case, it contained many additional morally relevant details beyond simply Knox and Sollecito’s physical involvement in Kercher’s murder.
For the reasons I just discussed, your probability distribution seems inconsistent with the evidence. Specifically, you rescue Knox and Sollecito’s guilty from possible errors by the prosecutor by proposing a theory that even you think has only a 5% chance of being true.
Agree.
I’m not sure what your point is here. Are we arguing about whether the prosecutor is competent? About whether he is unethical?
Do you agree that as a practical matter, in order to have a good chance of securing a conviction, a prosecutor needs to present a coherent narrative to the jury?
I don’t understand this sentence. I’m reluctant to guess at what you mean, but please keep in mind that “prosecutor correct” can be taken different ways. Does it mean simply that he is correct about physical involvement; or does it mean that his entire narrative is substantially correct?
My previous post was trying to define what I meant by correctness for the purpose of the probability analysis I did. In brief, a prosecutor is correct if the theory presented to the jury contains no morally relevant facts that are contradicted by what actually occurred. (To clarify what I mean by moral relevance: Did the burglar go in the unlocked front or unlocked back door? Legally relevant, but not morally relevant).
Thus, I think the answer to your question is that the prosecutor is incorrect if the narrative does not correctly describe what actually occurred. As I noted above, the prosecutor’s incorrectness is not inconsistent with the defendant’s legal guilt. But I assert that prosecutor’s incorrectness is suggestive of legal innocence because it shows the prosecutor doesn’t know what happened.
Sure, juries like stories. That isn’t precisely a rationalist feature of juries.
In the Kercher case, the prosecutor’s case was filled with morally relevant facts (e.g. the sex cult/orgy thing) that were wildly implausible and not supported by any evidence that I’m aware of. Then, more plausible assertions (i.e. it was impossible to enter the apartment via the fire escape) were contradicted. Since I independently believe that (P(defendant guilty of charged crime) & P(prosecutor incorrect)) is small, I’m left to estimate a very small likelihood that Knox is guilty.
Fine, but you don’t get to redefine the terms I used and then use your different definition to conclude that my probability estimate doesn’t make sense. That would be a fancy way of strawmanning me.
When I basically agreed that I believe that P (prosecutor correct) is 85%, I was careful to make clear what I meant by “prosecutor correct.” Please do not pretend that I meant (or that we were discussing) something different.
It was not my intent to strawman you. I seem to have misunderstood your position. Let’s return to basics.
Let’s define “no orgy, but guilty” as the state in which Knox and Sollecito are legally guilty of Kercher’s murder, but many of the prosecutor’s asserted morally relevant facts are false. By definition:
P(guilty) = P(prosecutor correct) + P(no orgy, but guilty)
P(no orgy, but guilty) = P(prosecutor incorrect) & P(guilty) [If I understand the terminology correctly]
Since you seem to agree that the prosecutor made incorrect assertions of morally relevant facts, your value of P(prosecutor correct) is negligibly small. Why do you think that the prosecutor made the assertions? Before you say “narrative,” let me assert that many of the prosecutor’s assertions could have been replaced with “I don’t know” with limited loss of coherence to the narrative.
Can you give me a specific example?
Ok, you’ve said it. And now my answer:
Narrative. I do agree that the prosecutor could have omitted a few things and still had a somewhat coherent narrative. But if he got rid of all the speculation, what he would be left without any motive or explanation for why Knox and Sollecito acted in concert with Guede.
Quoting wikipedia: “[The prosecutor alleged] that the murder was part of a Satanic ritual; that it was a sex game gone wrong; or that Kercher had refused to take part in an orgy.”
Honestly, a substantial part of my doubt of Knox and Sollecito’s guilt is the utter ridiculousness of those allegations. They were not necessary to provide narrative to the jury and could easily have been omitted, since there was apparently no evidence suggesting they were true.
Further, they are the type of allegations I would expect when the prosecutor is seeking to inflame, rather than rationally presenting the evidence.
Ok, to answer your question, I believe that the prosecutor made these assertions because he felt pressure to answer the question of Knox and Sollecito’s motives.
Satanic ritual? The prosecutor could have just said, “The roommates had a big fight.” In terms of evidence of guilt, there are two major problems in the “satanic ritual” theory that are not present in a more mundane theory. The satanic ritual theory proves too much, in that there is almost no evidence that could possibly be inconsistent with it. Second, the theory functions to demonize the defendants, which is not consistent with strong actual evidence of guilt.
And those theoretical arguments ignore the practical fact that there was no evidence suggesting interest in satanic ritual by either defendant, which I consider important given the general implausibility of the theory given what I know about society (There are practically no murderous satanists in real life).
Apparently he did also propose more mundane motives. Here’s the full quote from Wikipedia:
When you quoted Wikipedia, why did you omit the part about the cleaning roster?
Because I’m interested in why the prosecutor kept talking after he articulated that theory.
Either theory is just speculation, agreed? I mean, if it’s unethical for the prosecutor to argue that there was a satanic ritual, it’s also unethical for him to argue that it’s a dispute over who should clean the apartment. Agreed?
I’m not trying to say the prosecutor is unethical. I’m saying that outlandish claims from the prosecutor are evidence of innocence. It’s just a Big Lie
And if the prosecutor really has no idea why defendant committed a crime, that’s also evidence of innocence, right?
One could rationalize the prosecutor’s behavior by saying that lower standards apply to statements to the media than statements in court. But the reason that it’s unethical to try cases in the media is that this reduces the likelihood that the trial will be correlated with the truth. I attribute knowledge of that principle to the prosecutor, so his decision to try the case in the media suggests that the defendants are innocent.
Ok, I thought we were discussing whether the prosecutor was ethical.
I agree. And the decision to arrest Knox is evidence of guilt.
We were discussing whether the prosecutor is competent.
No, it isn’t. The decision to arrest is evidence that the authorities think they have evidence of guilt. But the arrest is not independent of the underlying evidence and does not make the underlying evidence stronger.
Ok, then why are you bringing up the question of whether the prosecutor’s assertions are evidentiary?
Similarly, the prosecutor’s proposal that there may have been a Satanic ritual involved is not independent of the underlying (lack of) evidence of motive and does not make the underlying evidence weaker.
The prosecutor’s theory is not evidence of the same type as DNA. But it tells us something about how strong the prosecutor thinks the legally relevant evidence is.
The reference to satanic ritual and sex games is an appeal to applause lights. It is political machinations, not an empirically based search for truth. The fact that the prosecutor made that appeal, rather than sticking with a plausible story, shows that the prosecutor doesn’t think the facts support guilt or doesn’t care.
As an observer, I’m allowed to give weight to the fact that one side of a dispute doesn’t seem to be trying to determine the facts.
A prosecutor will always make the strongest case they think they can, and juries do not comprise perfect rationalists.
The decision to arrest the defendant is not the same type as DNA. But it tells us something about how strong the authorities think the legally relevant evidence is.
I would say the amount of weight depends on the extent you are relying on unsupported assertions of that side. For example, if we knew nothing at all about the case except the prosecutor saying “Trust me, I have reviewed the evidence and I am satisfied that the Defendant is guilty, it would be very important that the prosecutor is proposing a seemingly outlandish hypothesis.
This is the expertise problem. You and I do not have access to all the evidence, so we look to the experts. If anyone is an expert on the strength of the case, it is the prosecutor. And a prosecutor referencing satanic rituals and sex cults is like a psychologist referencing the “Niceness Gene” to explain some behavior. It isn’t impossibly wrong, but it strongly suggests the expert doesn’t know what he is talking about.
So in your view, any probability assessment of Knox’s guilt which does not put a lot of weight on the prosecutor’s credibility is deeply flawed. Agreed?
No. The physical evidence does not support Knox’s guilt. But the fact is that the prosecutor and other Italian authorities are engaging in a lot of motivated cognition to support the theory of guilt even when the evidence doesn’t support it.
The motivated cognition is so blatant that it persuaded me that Knox was probably not guilty even before I looked at the evidence. I suspect that if the world were more rational, my reasoning would be less likely to provide useful insight.
How do you know this if you do not have access to all of the evidence and therefore must “look to the experts”?
It seems to me that you and I both have access to enough of the evidence to make a decent estimate of the probability of Knox’s guilt without relying on someone who has superior access to the evidence.
I’m not sure I would agree with this, FWIW.
My estimate of how ethical it is for a prosecutor to propose theory X about a defendant’s motive increases with how common X is, and decreases with how sensational X is. Roommates arguing over cleaning an apartment is both more common and less sensational than satanic rituals, so my estimates of how ethical it is to propose those theories differs.
Of course, maybe there’s some particularly salient threshold that both examples exceed. If so, it’s worth articulating that threshold explicitly… when it comes to propounding theories about motive, it’s not clear to me what that threshold is or ought to be.