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Another scientific body has debunked bitemark analysis
- vanattab 4y agoHow offen are people bitting people and only being id through the bite marks? Are there people sneaking into bedrooms biting people? I don't get it.
- rossdavidh 4y agoTypically it's a "man bites dog" kind of case. [ducks]
- mypalmike 4y agoWhen there are violent struggles, it's not actually that uncommon for bite marks to be present on victim or assistant. *Source - I've seen lots of episodes of Forensic Files.
- mypalmike 4y agoToo late to edit but... *assailant
- beastie29a 4y agoThere was an HBO documentary series named Autopsy[0] I watched back in the 90s and two crimes stick out. The series mainly followed the case file of a Forensic Pathologist named Dr. Michael Baden. If I can remember them correctly, one case was a murder that appeared as a break-in and a bite marking found on a garbage bag was tied back to the victim. The other was an inmate that left bite marks on a guard and tied the crime back to the inmate with. It’s so interesting to see this research now and wonder what would come of those cases now that the main evidence is seemingly unreliable. [0] https://www.hbo.com/autopsy https://www.hbo.com/autopsy
- OkayPhysicist 4y agoI'd imagine it's not uncommon for bite marks to be at least one piece of evidence. Victim struggles, bites assailant, cops arrest somebody with a bite mark, suspect insists it's from some fun times with their SO and not from a victim defending themselves, cops call upon their pseudoscientists to "prove" that the bite mark came from the victim. Or another way around, a victim of a violent assault might have been bit while fighting off their attacker. In a grappling scenario, there is definitely a portion of the population who will instinctively use their teeth, from my experience in water polo, I'd reckon about a quarter of people.
- MezzoDelCammin 4y agodo people in water polo really bite each other? Sounds pretty vicious...
- consp 4y agoI've seen it happen once in over 15 years of playing it on a "Beer-team" level. 25% sounds a bit much but YMMV for region to region and level of play.
- OkayPhysicist 4y agoMaybe. Might also have something to do with your position. I was a whole set/whole D/bruiser for my high school teams, so I spent a lot more time in direct contact with other players than most.
- OkayPhysicist 4y agoIt's a vicious sport. More so in women's polo, where the brute strength range is a lot smaller than in men's. I played at the highschool level, where the violence is vicious, as opposed to the university level where I'd better describe it as "brutal". Players treat the game as team vs. team vs. referee, so it's basically a melee until you think you can flop a bit to get the ref to kick an opposing player out.
- smcl 4y ago
- quickthrower2 4y agoSome criminals MO is to bite. Before DNA testing was available, it might be all the cops had as evidence. My person opinion is it is only good enough for a clue, not evidence. I think the same of the blood spatter patterns and when cops do reconstructions of things to determine what happened.
- banannaise 4y agoBloodstain analysis is, for the most part, also crap. [0] We should be wary of many of the types of physical "evidence" popularized by crime shows; many of them are backed up mostly by propaganda rather than science. [0] https://scholarship.shu.edu/cgi/viewcontent.cgi?article=2125&context=student_scholarship https://scholarship.shu.edu/cgi/viewcontent.cgi?article=2125...
- deleted 4y ago[deleted]
- Hackbraten 4y agoThe murder of Sherri Rasmussen [1] comes to mind. They caught the perpetrator decades later, mainly due to DNA traces left in the bite mark on the victim’s arm. [1]: https://en.wikipedia.org/wiki/Murder_of_Sherri_Rasmussen https://en.wikipedia.org/wiki/Murder_of_Sherri_Rasmussen
- irsagent 4y agoAre any implications drawn from these findings from a dentist perspective?
- 8f2ab37a-ed6c 4y agoI'd be curious to see a list of all of the classic cinema police cliche's that have no basis in evidence. So far there's the lie detector, blood spatter analysis, bite marks.. what else?
- JoeAltmaier 4y agoWait - blood spatter must follow the rules of physics, so there is some kind of analysis that would be valid, surely? Reading online I see its still respected lots of places and still taught in forensics. Don't know where that came from.
- agf 4y agoI think if you read this article you'll see (at least part of) the answer. Not only does a given action have to cause a definable result, the medium upon which the result is deposited has to provide enough detail to read the result back off it, and the people reading the result have to be able to be consistent and accurate in their analysis of that result. With bite marks, the skin has to hold the bite mark (which it doesn't) and experts have to be able to map it back to real human teeth (which they can't). With blood spatter, there are analogous problems.
- JoeAltmaier 4y agoWhich sounds miles from 'have no basis in evidence'. So that might have been a little hyperbolic.
- snapcaster 4y agoI'm not sure why you're trying to play devil's advocate on that. The things they are claiming about the analysis techniques literally have no basis in evidence. Saying "blood spatters follow laws of physics" has nothing to do with what the experts are doing now
- JoeAltmaier 4y ago
- nova22033 4y agoProves the main thesis of his excellent book The Cadaver King and the Country Dentist: A True Story of Injustice in the American South https://www.amazon.com/Cadaver-King-Country-Dentist-Injustice/dp/161039691X https://www.amazon.com/Cadaver-King-Country-Dentist-Injustic...
- kuprel 4y agoBite marks were used to convict Ted Bundy
- helloSirMan 4y agoSo no way to be sure if I bought Jon Voights car?
- 2bitencryption 4y agoI've been listening to the podcast Your Own Backyard (yes, I occasionally indulge in true crime, sue me!) There was recently an entire episode dedicated almost entirely to cadaver dog testimony. Well, the dog was not testifying, the handler was. Now, I have no doubt that cadaver dogs can, and do, find cadavers, and can detect when a cadaver was recently present. But listening to the testimony of the handler, from their viewpoints, the cadaver dogs are psychic. The ability of their senses verges on mysticism. I don't doubt that there is value to cadaver dogs - clearly they work, and get results. But the humans who testify on the dogs' behalf have a cult-like behavior about what the dogs can realistically detect, and how they interpret the dogs behaviors.
- TheSpiceIsLife 4y agoSome of the humans, the subset who's testimony was selected to appear on that show.
- giantg2 4y ago"... and how they interpret the dogs behaviors." The interpretation part is huge in many disciplines. If you especially look at high profile cases, you can have experts for each side presenting opposing interpretations (not even involving animals). Then it's up to the jury to decide which is more believable. There's your spooky story for the day.
- lcnPylGDnU4H9OF 4y agoAnd, unfortunately, "reasonable doubt" is not a reliable fallback in such a situation.
- giantg2 4y agoReasonable is whatever they say it is.
- FpUser 4y agoSo it seems that "beyond the reasonable doubts" is a fiction unless one can afford really expensive lawyers.
- holiveros 4y agoMexican here, in my country these type of "evidences" are harder to support / enforce, as long as your lawyer / you are willing to provide enough scientific indication they're not reliable, those evidences are dismissed. Of course, as any country, there's corruption at every level. Wonder what's the stance of other countries?
- bombcar 4y agoOften these types of evidences are used to get the subject to confess or agree to a plea deal. (In other words, they're often used "when we know you did it" kind of things.) The justice industry isn't very pretty, best not to look too closely at it.
- pyuser583 4y agoI’ve heard the Mexican legal system has really strong rights for defendants. So strong, it’s hard to prosecute corrupt officials.
- boxed 4y agoFound a spelling/grammar/idiom error ("little to know" -> "little to no"). Tried to commend, but I have to pay for that. Tried to click to that persons profile. Have to create an account. This seems like a bad idea...
- cobaltoxide 4y ago> Tried to commend ironic
- jobigoud 4y agoMuphry's law at play.
- ALittleLight 4y agoThis seems like a really straightforward thing to test. If I get a thousand people together, have them each bite 10 human skin analogues, identify the participants and each of their bite records with a GUID, can bite mark analysts map bite records to biters and with what accuracy? If they can't, why did the courts think they could? Why are we doing the tests for whether or not a method works after making use of that method? After skimming one of the papers linked in the NIST analysis - it seems bite mark analysis is far below this standard. The analysts being tested had substantial disagreements over whether something was a bite mark and whether it was caused by adult or child teeth. Matching bite marks to a reference mark seems well out of reach.
- chmod775 4y ago> This seems like a really straightforward thing to test. If I get a thousand people together, have them each bite 10 human skin analogues, identify the participants and each of their bite records with a GUID, can bite mark analysts map bite records to biters and with what accuracy? Not quite the same thing. Because that assumes you already know it was one of those people. More appropriately you should ask the labs "does this bite mark fit any of these 100 people", where none of those people actually caused the bite mark. Will the lab recognize it was none of them? If they just falsely identify one out of the hundred, that extrapolates to millions of people.
- gubernation 4y ago
- the_doctah 4y agoWhat? Are you saying Ted Bundy was innocent? The guy who escaped police custody and proceeded to the nearest sorority house to bludgeon three girls to death in their sleep?
- Jenda_ 4y agohttps://en.wikipedia.org/wiki/Annie_Dookhan https://en.wikipedia.org/wiki/Annie_Dookhan I find it shocking that there is no "continuous quality assurance" of these labs - for example, one should take the lab as a blackbox, and send 10% known-negatives, 10% known-positives, and 10% random samples from previous batches in every batch, and then evaluate a) how many known positives/negatives turned out right, b) how many samples from previous batches return the same result.
- dsfyu404ed 4y agoThis is just another case of one of those typical double standards that arise from existing in a society where a non-trivial fraction of the population is willing to give the government a free pass for anything short of chucking puppies into a wood chipper on a live stream. You can bet your ass if these labs were in the business of supplying defense attorneys the info they need to get clients found innocent they'd be QC and government-regulated up to their eyeballs and would get shut down at the drop of the hat for doing shoddy work. See also: Many telecoms and ISPs will happily provide police records with little formality. If a defense attorney wants to see all the records the cops got (not just the ones that are going to be used by the prosecution in court) they're pretty much up shit creek until a judge tells the business to turn them over.
- jmnicolas 4y agoI think there's also the problem of science that has been elevated as a religion and anything labelled scientific is taken as gospel. We should all remember this study that showed that 90% of scientific papers weren't reproducible (not science then). While I have no problem with science itself, scientists are humans, they make mistakes and can be bought.
- lo_zamoyski 4y agoPeople have trouble with moderation because moderation requires the skillful exercise of prudential judgement, and since prudence is a virtue, it means that it is something learned and acquired. That we can't verify everything personally and therefore must often rely, for practical reasons, on appropriate trust toward authority does not mean we ought to jump out of the pan of irrational skepticism into the fire of uncritical subservience.
- WaitWaitWha 4y agoGood. I am not saying forensic ballistics is just as pseudo-science, but it also needs a hard look to re-validate the deductions and now-accepted methodologies.
- skc 4y agoHeh, I used to watch true crime documentaries pretty religiously at one point. But the more I read about just how flimsy the science behind some of these forensic techniques was the less comfortable I felt until I pretty much stopped watching altogether.
- umvi 4y ago> The field has a horrendous track record: More than two dozen people arrested or convicted with bitemark evidence have since been exonerated. It's probably true that bitemark analysis is ineffective at identifying biters, but I would appreciate it if the full data picture were painted. 2 dozen people out of how many total? It's like saying "X vaccine has a horrendous track record: more than 50 people have died after receiving it". 50 out of how many? If 200, that is indeed horrendous (25% death rate), but if 50 million, then it's not horrendous (0.0001% death rate). Let me be the judge of what is horrendous or not by giving me full context.
- PebblesRox 4y agoFrom the article, seems like only a few hundred cases: “Bitemark analysis has been used only in a small percentage of criminal convictions...At worst, it would require the re-opening and reinvestigation of a few hundred cases.
- luxuryballs 4y agoI’m surprised that this even needed a study, which also makes it rather alarming.
- Zigurd 4y ago"Crime labs" cannot be trusted. They are unaccountable and dependent on police departments for funding. Their results are "good" if people get convicted. That's perverse and contrary to scientific principles. That extends to publications in that field. It's systemically corrupted and needs to be restructured to be independent of police and prosecutors.
- cybervegan 4y agoThis little eggcorn in the article made me chuckle "little to know" (should be "little to no").
- adamgordonbell 4y agoTIL about eggcorns. a word or phrase that results from a mishearing or misinterpretation of another, an element of the original being substituted for one that sounds very similar or identical (e.g. tow the line instead of toe the line ). I have a version of this all the time when writing but it doesn't match that definition. For me, it's more like my writing is transcribing an internal auditory dialogue and my inner voice might be saying 'their' but my transcriber will write 'there'. So, it's not that I don't know what's right ( or write ) but that it comes out wrong without active rereading. Does anyone else have this?
- luxuryballs 4y agoI’m surprised that this even needed a study, which also makes it an little alarming.
- joering2 4y agoThe ultimate downfall of a society.. when justice system simply becomes just a system, out of convenience.
- kazinator 4y agoBitemark analysis for which child got into the block of cheddar cheese is dead accurate, though. You will not so easily overturn the convictions.
- jeff-davis 4y agoIs this just a general problem in science? Science is highly objective, but the process of attaining scientific credibility is prone to all kinds of human problems. Expecting the judicial system to sort through this better than the scientific community seems foolish. Ideally, a high-enough percentage of scientifically-educated people would mean more skeptical jurors, defense attorneys who more able to challenge experts, and judges more able to keep junk science out entirely.
- semilattice 4y agoLack of incentives for scientific skepticism as a normalized, institutionalized form of academic discourse -- is the problem. The are a lot of incentives to get 'published' or to get 'sponsored. And there are no incentives to question validity of methods or results (unless these are 'sponsored'). Formalized methodology underpinning scientific skepticism, should be taught as part of first 4 years of college (or even specialized vocational schools). There are should magazines in every field, dedicated to skepticism, the recent discoveries, methods of analysis, etc. There are should be commercial and tax-payer funded sponsorships available to do just that. May be, there should be advanced degrees in statistical claim validation methods, and so on.
- 2devnull 4y agoI sometimes worry that we don’t have a culture of science, but a culture of scientists. Very different things in terms of aggregate output.