# Was Amanda Knox Involved In Any Way With Her Roommate's Murder? **URL:** \ **Category:** Great Debates\ **Created:** [September 28, 2011, 5:39pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906 "2011-09-28T17:39:50Z")\ **Posts on this page:** 20\ **Page:** 14
**Author:** ![DragonAsh](https://avatars.discourse-cdn.com/v4/letter/d/db5fbb/32.png) [@DragonAsh](https://boards.straightdope.com/u/DragonAsh)\ **Post date:** [October 7, 2011, 3:31pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/261 "2011-10-07T15:31:28Z")
> [@Marley23](#): > > I allowed a couple of comments like this earlier in the thread, but I’m going to say now that it’s off limits. Commenting on a poster’s argument and its implications is fine, but when there’s too much commentary on what the argument says about the person, it’s a short step to flaming. No more of this, please. And the same goes for this: > And **Snowboarder Bo** , I admit I asked the same question **Gary Kumquat** did upthread, but I’m instructing you to just answer it. You’re not even being asked to defend an argument, you’re being asked to explain the basis for your opinion and I can’t think of a good reason you are refusing to post that. Bah. OK, I’ll apologize too - although I’ll protest that I was trying to make a point about how people can get wrongly convicted. ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [October 7, 2011, 3:33pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/262 "2011-10-07T15:33:42Z")
> [@DragonAsh](#): > > A test for a disease is known to be accurate 99% of the time. > > We pull a person at random off the street and give him the test, which comes back positive for the disease. > > What is the probability that the person has the disease? Do you have access to any other information? ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [October 7, 2011, 3:39pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/263 "2011-10-07T15:39:17Z")
> [@Fotheringay-Phipps](#): > > As noted earlier, this is a distinction without a difference (for our purposes). > > For some reason, you’ve declined to address this and explain why you think this distinction matters. I don’t agree. This distinction is always relevant. > [@](#): > > ETA: the bottom line of both situations is that the likelihood that a series of unrelated plausible events took place is less than the likelihood that any one of them took place. No, it’s not, because before you get to the question of the likelihood of whether a series of plausible events was unrelated, you have to first show that any one of those events actually happened at all. If they didn’t happen, it doesn’t matter whether it’s unlikely that they might have been unrelated. This is what I meant by bootstrapping. You’re piling conjecture upon conjecture and then acting as if there is something to answer for. This is exactly what conspiracy theorists do. - There is an uncorroborated claim that A saw a bright light in the sky. - There is an uncorroborated claim that on the same night B saw an unmarked, military-looking vehicle in the area. - There is a nearby military installation where top-secret activities take place. The Army never comments on what goes on there. - Somebody once wrote a book saying that the army has often secreted evidence of flying saucers. - Etc. - All the “sources” for these pieces of evidence are highly unreliable in one way or another. Do you then pile up these individual pieces of unreliable evidence and say – “What is the likelihood that all these events could be unrelated to each other? Therefore, it is a reasonable conclusion that an extraterrestrial spacecraft landed and was taken into custody by the army.” ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 3:39pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/264 "2011-10-07T15:39:25Z")
> [@Acsenray](#): > > Here’s the problem. We’re not talking about evidence that standing alone shows that there’s a 50-50 chance that the defendant is guilty. We’re talking about evidence about which we’re only 50 percent sure that _that piece of evidence is true at all_. That’s true of most evidence. Maybe the chances aren’t 50%, but there is always a decent chance that an identification witness was coached or was flat out lying; or that DNA match was the result of lab contamination; or that the authorities manipulated the evidence at the scene; or that the police forensics expert is lying; or that a witness is mistaken or even lying. For example, the authorities in the Amanda Knox case asserted that in the “burglarized” room, the broken glass was lying on top of the ransacked belongings. What are the chances that this evidence is “true at all”? Similarly, the authorities in the Amanda Knox case assert that Sollecito called the police; advised them of the burglary; and stated that nothing had been taken before the room’s occupant returned and confirmed that nothing had been taken. What are the chances that this evidence is “true at all”? Or this: According to the authorities (as I recall), Amanda Knox advised them from the very beginning that Meredith Kercher normally locked her bedroom door when she went out of the room, even to take a shower or bath. At the same time, another roommate allegedly advised the authorities that Kercher pretty much never locked her door. What are the chances that this evidence is “true at all”? ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 3:41pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/265 "2011-10-07T15:41:10Z")
> [@DragonAsh](#): > > A test for a disease is known to be accurate 99% of the time. > > We pull a person at random off the street and give him the test, which comes back positive for the disease. > > What is the probability that the person has the disease? You would need to know what percentage of the population has the disease to answer the question. (Actually you would need to know what percentage of the population on the street at that time has the disease.) ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 3:42pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/266 "2011-10-07T15:42:15Z")
> [@steronz](#): > > Sure, it’s called the preponderance of evidence, right? What matters is that the individual pieces of evidence are credible. If everyone in the high school says that Sally is a tramp, it must be true, right? Because everyone says it. One person says it, it could just be a grudge, but if _everyone_ says it, well, tramp she she is, right? Or maybe we should sit down with every single high-schooler and figure out if they’re basing their accusations on anything more than rumor. If not, we should throw out the whole lot, no matter how many there are. Does that mean yes or no? ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [October 7, 2011, 3:51pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/267 "2011-10-07T15:51:02Z")
> [@brazil84](#): > > Does that mean yes or no? It means that 30 girls who are repeating the same rumour is no more persuasive than one. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 3:57pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/268 "2011-10-07T15:57:11Z")
> [@Acsenray](#): > > It means that 30 girls who are repeating the same rumour is no more persuasive than one. I basically agree with that statement, but it’s not an answer to my question. Do you deny that situations can and do arise where one can be reasonably confident about a certain conclusion based on numerous pieces of evidence each of which considered in isolation is inconclusive? ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [October 7, 2011, 3:57pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/269 "2011-10-07T15:57:47Z")
> [@Acsenray](#): > > No, it’s not, because before you get to the question of the likelihood of whether a series of plausible events was unrelated, you have to first show that any one of those events actually happened at all. If they didn’t happen, it doesn’t matter whether it’s unlikely that they might have been unrelated. You’ve misunderstood. In this case, the “event” is the alternative theory of evidence. In the example I gave earlier, you’re conjecturing that contamination caused the accused DNA to get on the victim (or murder weapon, whatever). That’s an “event”, which has a likelihood which is considerably less than 100%. Let’s say it’s 50% likely. Now suppose there’s another piece of evidence with the same type of DNA evidence (in another location/lab etc., so that it wouldn’t be the same contamination we’re discussing), and you need to conjecture that in this case too the DNA was the result of contamination. And suppose in this case too, the likelihood is 50%. Now consider the likelihood that both pieces of DNA evidence came about through contamination. The likelihood here is reduced to 25%. In such a case, the likelihood that all the DNA came about through the one reason (the accused is guilty) becomes stronger as the alternative explanation (contamination) becomes less likely. And so on, for more (independent) conjectures and other types of evidence. > [@](#): > > Do you then pile up these individual pieces of unreliable evidence and say – “What is the likelihood that all these events could be unrelated to each other? Therefore, it is a reasonable conclusion that an extraterrestrial spacecraft landed and was taken into custody by the army.” Firstly, that’s not all of what ET theorists are doing, and there’s a lot more to the issue than what you suggest. But beyond that, you’re missing another point. As I alluded in my response to DragonAsh earlier, evidence is not considered in a vacuum. Even if in a given case the conspiracy theorists have legitimate evicence, it needs to be weighed against any other evidence available, and against the a priori likelihood of a given theory being true. [On that topic: it should be noted that - WRT to DNA testing and the like - that the following two statements are not at all the same: [ul] [li]The likelihood of X happening due to chance are one in a million[/li][li]The likelihood that X has happened due to chance is one in a million[/li][/ul] These are very fundamentally different, and ISTM that many people fail to appreciate this.] As too in this case. If the only way Knox could have been involved in the murder was with the help of extraterrestial friends and their/her super powers or some other equally unplausible scenario, then the strength of that would outweigh the evidence against her. As it is, there’s very little to make the scenario far-fetched, IMO. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [October 7, 2011, 4:02pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/270 "2011-10-07T16:02:37Z")
> [@brazil84](#): > > I basically agree with that statement, but it’s not an answer to my question. > > Do you deny that situations can and do arise where one can be reasonably confident about a certain conclusion based on numerous pieces of evidence each of which considered in isolation is inconclusive? If “inconclusive” means “unreliable” or “not credible” or going to some fault as to the truth of the evidence itself, then I do deny it. If “inconclusive” means only “ambiguous” or “capable of supporting multiple possibilities” then that’s a different story. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 4:11pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/271 "2011-10-07T16:11:57Z")
> [@Fotheringay-Phipps](#): > > As it is, there’s very little to make the scenario far-fetched, IMO. Except for the fact that it’s unusual for one hot girl to murder another hot girl. Besides that, I basically agree with your argument. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 4:19pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/272 "2011-10-07T16:19:46Z")
> [@Acsenray](#): > > If “inconclusive” means “unreliable” or “not credible” or going to some fault as to the truth of the evidence itself, then I do deny it. > > If “inconclusive” means only “ambiguous” or “capable of supporting multiple possibilities” then that’s a different story. When I state that a piece of evidence in isolation is inconclusive, I mean that looking at it alone, one cannot be reasonably confident of one’s conclusion. Regardless of the reason for that lack of confidence. For example, just the fact that Mac had bought life insurance on his associate, standing alone, is inconclusive. ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [October 7, 2011, 4:20pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/273 "2011-10-07T16:20:41Z")
> [@brazil84](#): > > Except for the fact that it’s unusual for one hot girl to murder another hot girl. I consider that “very little”. It’s unusual for anyone to murder anyone else. Once a murder has taken place, the only question is who did it. It’s undoubtedly more unusual for yound middle class girls to murder one another than many other types of people, but it’s not remotely unlikely in the manner of ETs. ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [October 7, 2011, 4:31pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/274 "2011-10-07T16:31:22Z")
> [@brazil84](#): > > When I state that a piece of evidence in isolation is inconclusive, I mean that looking at it alone, one cannot be reasonably confident of one’s conclusion. Regardless of the reason for that lack of confidence. > > For example, just the fact that Mac had bought life insurance on his associate, standing alone, is inconclusive. Nobody gets convicted on one piece of evidence alone. If Law and Order taught me anything, it’s that the prosecution needs to show means, motive, and opportunity. The life insurance policy would be motive, the EZ-Pass records would be opportunity, and the murder weapon would be the means. 2 out of the 3 wouldn’t be enough to convict, but all 3 would. Note that here we only have 3 pieces of evidence, but they’re _very good_ pieces of evidence. It’s not the number, it’s the quality, and the fact that all the facets of the crime are met. 1000 pieces of shitty evidence is still worthless. I’m not sure what you’re looking for with a yes or no answer, but my stance on the issue should be obvious at this point. ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [October 7, 2011, 4:32pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/275 "2011-10-07T16:32:41Z")
> [@Fotheringay-Phipps](#): > > Firstly, that’s not all of what ET theorists are doing, and there’s a lot more to the issue than what you suggest. I’m not sure what this is supposed to mean. It’s certainly what a lot of alien conspiracy theorists are doing, but the point is the type of reasoning being illustrated. > [@](#): > > [ul] > [li]The likelihood of X happening due to chance are one in a million[/li][li]The likelihood that X has happened due to chance is one in a million[/li][/ul] > These are very fundamentally different, and ISTM that many people fail to appreciate this.] I’m not sure what you’re getting at but at first pass I don’t see any reason to accept the bare claim that these are fundamentally different. > [@](#): > > As it is, there’s very little to make the scenario far-fetched, IMO. The question is not whether the scenario is far-fetched. The question is whether there is sufficient evidence to prove that the scenario happened. > [@Fotheringay-Phipps](#): > > It’s undoubtedly more unusual for yound middle class girls to murder one another than many other types of people, but it’s not remotely unlikely in the manner of ETs. Again, the question is not whether the overall scenario is unlikely, but whether you can stack pieces of shaky evidence in order to reach a reasonable inference. > [@brazil84](#): > > When I state that a piece of evidence in isolation is inconclusive, I mean that looking at it alone, one cannot be reasonably confident of one’s conclusion. Regardless of the reason for that lack of confidence. This is not sufficiently specific. > [@](#): > > For example, just the fact that Mac had bought life insurance on his associate, standing alone, is inconclusive. If you have an actual copy of the contract, an admission by Mac that he bought the insurance, the testimony of the insurance agent, etc., it is valid indirect evidence that might be legitimately relied upon, but it is not by itself conclusive. But if no one can locate the copy of the insurance contract, Mac’s business records are sloppy and confused, the insurance agency clerk failed to record the transaction, and the only evidence you have that the insurance thing actually happened is that Mac’s ex-wife who is suing him for custody says she overheard Mac telling someone that he was going to buy life insurance, then it is not merely “inconclusive” evidence, but it is evidence that is not credible or reliable even as indirect evidence and cannot be added to other indirect evidence in the same way. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 7, 2011, 4:35pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/276 "2011-10-07T16:35:16Z")
> [@steronz](#): > > the prosecution needs to show means, motive, and opportunity. That’s a myth. The three together are insufficient, and none individually is necessary. They help… But motive especially is not required for conviction. ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [October 7, 2011, 4:37pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/277 "2011-10-07T16:37:09Z")
> [@Frylock](#): > > That’s a myth. The three together are insufficient, and none individually is necessary. > > They help… But motive especially is not required for conviction. Sam Waterston wouldn’t lie to me! I won’t have it! ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 4:38pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/278 "2011-10-07T16:38:15Z")
> [@Acsenray](#): > > This is not sufficiently specific. So you do not agree that situations can arise where you are reasonably confident of a particular conclusion based on multiple pieces of evidence, each one of which when considered alone does not give rise to reasonable confidence in the conclusion (for any reason)? Oh, and please answer my other questions: 1. The authorities in the Amanda Knox case asserted that in the “burglarized” room, the broken glass was lying on top of the ransacked belongings. What are the chances that this evidence is “true at all”? 2. The authorities in the Amanda Knox case assert that Sollecito called the police; advised them of the burglary; and stated that nothing had been taken before the room’s occupant returned and confirmed that nothing had been taken. What are the chances that this evidence is “true at all”? 3. According to the authorities (as I recall), Amanda Knox advised them from the very beginning that Meredith Kercher normally locked her bedroom door when she went out of the room, even to take a shower or bath. At the same time, another roommate allegedly advised the authorities that Kercher pretty much never locked her door. What are the chances that this evidence is “true at all”? ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 7, 2011, 4:41pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/279 "2011-10-07T16:41:01Z")
> [@steronz](#): > > Sam Waterston wouldn’t lie to me! I won’t have it! Sorry, but he had the means, motive and opportunity, so… ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [October 7, 2011, 4:41pm UTC](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906/280 "2011-10-07T16:41:39Z")
> [@Fotheringay-Phipps](#): > > I consider that “very little”. It’s unusual for anyone to murder anyone else. Once a murder has taken place, the only question is who did it. It’s undoubtedly more unusual for yound middle class girls to murder one another than many other types of people, but it’s not remotely unlikely in the manner of ETs. I basically agree with this, but I still think that in weighing the chances of Knox’s guilt (or at least involvement in the murder), it’s reasonable to consider that the scenario where Knox, Sollecito, and Guede murder Kerchner in concert is much more far-fetched than the scenario where Guede acts alone. [Previous page](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906.md?page=13) [Next page](https://boards.straightdope.com/t/was-amanda-knox-involved-in-any-way-with-her-roommates-murder/597906.md?page=15)