Daniel Ravenscroft
I am a graduate of Biomedical Science at the University of Sheffield, and currently work at the University as a Demonstrator for Human Anatomy and Biomedical Science lab classes.
Location University of Sheffield
Activity
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Hi Christiejo, the links were just at the bottom of this article:
http://news.bbc.co.uk/1/hi/uk/1220446.stm
http://news.bbc.co.uk/1/hi/uk/1190207.stm -
Hi Debbie, I've not had chance to go through it yet but a number of learners have recommended the Identifying the Dead MOOC run by the University of Dundee.
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Hi Tony, I understand what you're suggesting, and think it would be quite appropriate if a statistical method could be defined. In fact I recently read a research paper that attempted to reveal the effect of the muscles of mastication (chewing muscles) on the bones of the skull - it suggested that larger muscles would leave visible differences on those bones....
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Daniel Ravenscroft replied to Jill Hind
Hi Jill, thank you for the suggestion, I'll certainly make sure it's passed on as I know there has been difficulty in following the pace of the video in 2.4.
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Daniel Ravenscroft replied to Susan Obeso
Hi Susan, if you were to carry out a facial reconstruction then yes, that information would be important (and they are roughly as shown on the images). On this course we are trying to introduce the technique as part of the Finding Mr. X investigation, so did not want to overload it with material. However, we appreciate the feedback and I'll make sure it's...
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Hi Diandra, that's a very comprehensive reply! Exactly, the tissue depth averages may be selected based on the factors you stated, resulting in different reconstructions.
Your suggestion of weight estimation is appropriate and I've had a similar discussion with other learners - the point you make about weight gain or loss is especially relevant as that is one... -
Hi Crisel, that's great and a lot of people are here because of their similar interest in crime TV shows! I hope you enjoy the course, but don't expect to be doing forensics as fast as the Flash!
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Hi Stephen, the marker pegs do use average tissue depths. Can you think why different averages may be used for different people?
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Hello Lavinia, if you remember in Week 1 we found out the body was an adipocerous mummy, requiring it to have been stored for at least several years.
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Jean that's a perfect example of how bias could be introduced into a reconstruction! I think we are all tempted to make things in a manner that is more familiar to us. Thank you for sharing your experience.
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Hi Margaret, a few people have also found the pace difficult. I'll pass on the feedback, but for now you may find it helpful to go through the next article which gives information on all the facial muscles, and then come back and watch this video again.
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This is a feeling shared by a lot of people! I haven't found an official attempt at this by qualified experts, but you all be very interested in this comment by Dr Linehan, the lead educator: https://www.futurelearn.com/courses/forensic-facial-reconstruction/1/comments/19500534
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Hi Carole and Pamela, thank you for feedback, it's appreciated that it is a lot of content to take in at once! The next article covers each muscle again, so you may find it beneficial to read through and then come back to this video.
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Hi Alysa, I hope you're able to find more courses you can take to satisfy your interests! Thank you very much for the feedback, I'll make sure it's passed along.
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Hello Ali, a facial reconstruction is very rarely the first choice in criminal investigations, but may be among the first things in an archaeological case. Can you suggest why or when a forensic facial reconstruction may be useful, despite the time and lack of specificity, in a criminal investigation?
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Vicky - the amount of wear at certain joints can be used to estimate the weight of a person. Without any soft tissue, the amount of fat would be very difficult to predict.
Really interesting isn't it! Clearly being able to accurately identify ethnicity is a really significant part of forensic archaeology. -
Yes Barbara I would agree that could be a limitation in identifying the person. And Matt that's a good point, hopefully as digital reconstructions become more prominent, doing something along those lines will become more achievable.
Barbara, I would add another possible risk could be if the forensics team are aware of a prime suspect, as it would be crucial... -
Margaret those are some great suggestions. If enough of the skull and dentition is present then hopefully these would be identified and treated appropriately for the reconstruction. Just as we saw with Mr. X and chewing khat, habitual behaviours that can be inferred from the skeleton can be really useful in assisting identification!
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Well Barbara I think what you're touching on is one of the most important considerations in avoiding the introduction of bias into a reconstruction. The use of tissue depth markers should help to avoid this, to some degree. Can you think of any other ways the reconstruction could be biased?
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Hi Margaret, there is some evidence to show that the thickness of the lips can be related to the shape and size of the teeth, including the height of enamel and differences between upper and lower teeth.
I'm afraid I don't know a lot about how similar the results of digital reconstruction are (but am following the field with keen interest, as it seems to only... -
Hi Matt, the difference in how the nose and mouth areas are reconstructed for individuals of the same ethnicity is more to do with the corresponding structures, for instance the nasal aperture (gap across the nasal bone) and the dentition (e.g. the size of the teeth). That would definitely be good to see! I think judging how to consider ethnicity in the...
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Hi Mary, average tissue depths do vary between ethnicities but this is not always the only consideration - often evidence that gives an impression of the individual's size and lifestyle can be just as important. In 2.7 there is a really interesting video with Professor Wilkinson in which she describes the software she uses to perform reconstructions. As these...
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I remember seeing your comment, a very logical suggestion! Even if the information did not directly contribute to Mr. X's identification, these theories were very important for corroborating the details of the case.
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Not easily Roger, though estimations may be made regarding how active they were, or if they suffered from medical conditions that would have resulted in such physical characteristics. As always, the amount of evidence available will help create a profile for the individual - perhaps in giving light on their medical history, or it could even be something like...
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Catherine thank you for noticing this, there was an error when the image was uploaded. You are right that the only attachments of Levator Labii Superioris should be the origin just below the orbits, and the insertion just above the upper teeth.
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Daniel Ravenscroft made a comment
There has been an error in uploading the image for Levator Labii Superioris - the only muscle fibres that should be present are the ones on the front, the pair that descend from just below the orbits to the upper lip (just above the upper teeth). Please ignore the fibres that seem to attach to the rear molars.
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Certainly if there is a photograph that would be very useful, and in the case of historical reconstructions (i.e. of known individuals) then things like photos, paintings and written descriptions would be used. However, even for people we do not know (so there would be no photographs to help) such as those hoping to be identified in a criminal investigation...
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Hi Anasuya, as we cannot know the exact thickness, average thickness based on age, sex and ethnicity are used. Also considered is any other information we may have found out about the individual, could you suggest anything that could be taken into consideration for a facial reconstruction?
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Hi Barbara, I know this is a lot of anatomical information in one short video, but hopefully the next article: 2.5 The muscles of the skull, will help you to process what you've just seen. Perhaps it would be best to revisit this video once you've had a look through that article.
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Hi Catherine, I'll try to confirm if that is an error, thank you for picking up on it.
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Hi Susan and John, the reason it is not normally included is simply because it makes little difference to the appearance of the reconstruction, not because of a lack of importance. Wrinkles are still added as artistic details in the skin layer.
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Hi Debbie, I just responded to a similar question. I don't know if such a thing has been tested in a formal setting, but you may be really interested to read this comment by our lead educator!
https://www.futurelearn.com/courses/forensic-facial-reconstruction/1/comments/19500534
I think your concerns are valid nonetheless, particularly features like lips... -
Daniel Ravenscroft replied to Catherine Schaus
Hi Catherine, sorry for the disparity - I looked this up after another learner picked up on it as well. The key condition for an adipocerous mummy is that it is stored in a "moist" or "damp" environment. In Professor Evison's report, he refers to a "cool, moist environment".
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Daniel Ravenscroft replied to Margaret Thornley
Hi Margaret, sorry for the disparity - I looked this up after another learner picked up on it as well. The key condition is that it is "moist" or "damp". In Professor Evison's report, he refers to a "cool, moist environment".
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I forgot to mention, the author of the above paper is Professor Caroline Wilkinson, who you will come across more in Week 2 of the course!
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Hi Bob. I think the short answer to your question is yes, but the context would be very relevant. Should the firearm or trauma have damaged the bones underneath the face, then the accuracy of any reconstruction would be greatly reduced. As you will see in Week 2 of this course, the bones of the skull are critical to how the muscles of the face are applied in a...
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Hi Kate, I can't comment on how similar they would always be, but here is a link to a comment by Dr Linehan (our lead educator) which you will probably find really interesting! Seeing as I was part of the class she refers to, I know I certainly did!
https://www.futurelearn.com/courses/forensic-facial-reconstruction/1/comments/19500534 -
Kathryn and Helen, here is a link to the article I mentioned https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815945/
This is one of many papers that comment on the accuracy and techniques involved in facial reconstruction. It is quite long, so I would suggest searching (Ctrl F) for "lips" and "nose" if that is what you are most interested in. I hope it helps to... -
Hi Emma, this could extend to a number of things. One of the most apparent would be if the forensics team were aware of a prime suspect, as if they're not vigilant, they could find that knowledge altering how they carry out the reconstruction (they would need to be careful not to allow it to change what they expect the reconstruction to look like).
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Hi Anthony, that's an interesting suggestion that I've not seen anyone else come up with. Farming the crop is a reasonable suggestion for what happened to his arm as well. Ultimately this case would always have to be treated under very suspicious circumstances due to the nature of his discovery and the condition of the body - both being found dumped in a bag,...
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Hi Kathryn, this is one of the most challenging parts of a facial reconstruction, and is often considered to take the most artistic licence. However, the nose is generally just slightly wider than the width of the nasal aperture (the gap across the nasal bone). The thickness of the lips consider features including the arrangement of the teeth and facial...
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That's right Maria, diet - particularly during childhood - will alter the development of the skeleton. Hormones do affect the formation of bones - significantly the effect of testosterone in males and oestrogen/progesterone in women, and how these result in the sex-defining characteristics that we explore in this course.
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Hi Pamela, that is essentially what can be inferred from some skeletons in regard to occupation/daily actions. However, as you'll see with Mr. X, this can often offer a clearer indication of the who the person is that you might expect!
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Pamela that's exactly the case. You may be interested to know that there are a number of bones in the skeleton that can be assessed for sex under non-visual parameters as well, such as weight and size. The 'range of definitions' is how I was taught to determine the sex of a skeleton - by defining to what extent each of the skeletal features that are present...
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Yes Katherine that is definitely one of the main considerations. Just like the skull, there are several characteristics of the pelvis that allow sex to be determined. Other bones, like the femur, can be assessed for their size and weight to make a prediction of sex.
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Hi Rebecca, plastic surgery would affect an attempted facial reconstruction, but may not affect what information is gained from the skeleton as much as one would think, given that the changes are mostly superficial (i.e. to the soft tissue, not the actual bones). Tracing the plastic surgery would definitely be something investigators would look to do if they...
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Hi everyone, perhaps you've already learned more as you go through the course. What we look for are interesting features on the skeleton, for example excessive wear of certain bones. This could suggest the person used those parts of their body much more than a normal person would, perhaps something tied in with their daily job. You'll find this is nicely...
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Hi Steve, we appreciate all the feedback and have been passing it on to our video team.
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Hi Michaela, these are some really interesting questions! Annoyingly they are probably quite tricky ones to answer - if Mr. X was living in another country, such as Yemen, I would be inclined to suggest it was a habit born of tradition. However, given his medical conditions that would have been likely causing him daily pain, perhaps he chewed the substance...
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Daniel Ravenscroft replied to Alun Rees
Alun, just to confirm - the key factor for an adipocerous mummy is that the conditions are moist - the waxy nature of the skin develops from the moisture in the air. In Professor Martin Evison's report on this case, he does refer to a "cool moist environment".
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What may be more apparent in the analysis Karlie is what Michaela has pointed out, as the development of the body may be at odds at what is expected from the skeleton due to factors such as muscle development.
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This is a really interesting discussion, and a thought that seems to be shared by several of your fellow learners! You are correct in suggesting that your friend's skeleton is unlikely to be visibly changed, although some facial reconstruction surgery does involve slightly altering the morphology of some bones (for example, the orbits and nasal bone). Should a...
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Hi Trudie, as Steve has suggested the sex of the body was identified using the body. In fact it was one of the first details about the subject that was determined. With Mr. X the forensics team were lucky to have a full skeleton, could you suggest what could be used to identify the sex of the body had the skull been missing? Had clothes been present, they...
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Hi Stephen and Maria. I'd also like to add that the biological profile would also extend to the way the skeleton develops regardless of additional factors throughout the individual's life - a clear visual example being the morphology of the bones.
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Hello Colleen, I think picking up on subjectivity is such a key consideration. Despite what may seem to be the more obvious factors - aesthetic details like those you've also listed - bias due to the ongoing investigation can prove to be even more significant.
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Amazing isn't it! It's a very rare condition that seems to be associated with repetitive use over a very long period, and so it's no surprise that it was focused on in the attempt to identify Mr. X!
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You raise a very good point Colette, and it's one of the main reasons that multiple reconstructions are often made. Clearly objectivity is one of the most important factors in performing a reconstruction.
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Interestingly Rita, that could actually be a clue as to his identity. Perhaps the reason he hasn't been linked to missing persons reports is that he wasn't from the area, or maybe he had stayed away from public contact for some reason. It's worth considering these matters, because as Helen points out, normally someone would notice a person that goes missing,...
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Hi Stephanie that's a really interesting thought, and could shed light on his identity. Just to clarify, the mummification is something that would have taken place post-mortem though.
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Hello Olayinka, damage to the skull or missing part of it could affect how confidently the sex of the individual is determined. However, unless the skull is all that is present of the skeleton, this should not significantly affect the determination of sex. Can you suggest why this would be?
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Thank you all for you feedback, we have been taking these comments on board in regard to improving the videos.
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Ultimately no single feature could be used to discriminate the sex, so a combination of features would always be used, depending on how much of the skeleton is present. This is a feature that could be used, but as it is fairly vague when considered independently (i.e. 'large' or 'small'), it is not as clear as the other characteristics listed in this article....
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Hello Anthony, I believe you are referring to the mandibular condyles, the top end of the mandible that appears to project toward the zygomatic arch (this is the bone that looks to be going sideways from the side of the skull to the base of the orbit). These condyles tend to be larger in males, smaller in females.
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This started as a very interesting discussion, and has considered a number of important forensic details, but it would be best to finish here to avoid going off topic. You've all shown a really comprehensive perspective on the challenges facing facial reconstruction and the use of DNA evidence.
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Hi Jake, that's great and it's the same as what has interested a large number of the people on this course in forensics! I hope you're able to take what you learn and use it to assess how realistic the next crime drama you watch is.
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Being able to estimate how long ago the surgery in the toe was performed was helpful, though as several learners have pointed out - the type of screw that was used has not been used in this country for a long time, thus making it difficult to trace even the operation was performed here. Your line of thinking is very appropriate Dan, as attempting to trace his...
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These are great questions Sue, and ones the investigators will have spent a lot time try to answer as well! I think that looking at the conditions that would have resulted in an adipocerous mummy is definitely a good idea. We know that the location must have been moist, most likely somewhere with poor ventilation, so your suggestion of a cellar would seem...
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This has been a really engaging discussion. It is likely that should Mr. X have had treatment in this country for the more unusual of his conditions, then this would be flagged as part of the investigation into his medical records. As Richard has explained, should those operations have been undertaken elsewhere, then finding that sort of information can be an...
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Hi Erin, you're right - quite often a male skull may show feminine traits, and vice versa. By attributing each feature to a range of definitions (e.g. from definitely male to definitely female), the overall trend of a skeleton to what is normally expected of either a male or female can normally be determined.
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Hi Rose, the pelvis is often the preferred tool for identifying the sex of an individual. However, both the pelvis and the skull have dozens of features that can be used to help determine the sex. Furthermore, sex can be predicted from several other bones in the body, which is important as an entire skeleton will not always be present for analysis.
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Hi Catherine, some of the features can be considered under statistical parameters, if that is what you're asking. Though when I studied forensic anatomy, we would define each feature on a five-point range from "definitely male" to "definitely female". In doing so, we could account for features that were difficult to distinguish, and a clear trend could be...
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Hello Soo Yee Jing, what is meant is that these features often have a range of appearance, and some male features may appear feminine, and vice versa. In considering the appearance of many different features, the overall trend of a skull's characteristics can normally be observed to be either male or female. Surgery could alter the morphology of the skull,...
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Hi Anne, I think it is fair to say there is a clear shift toward computer-generated models, due to their accuracy and ease for editing. Additionally, the production of e-fits can be quickly made from the diital copies. The 3D printing of such reconstructions is however costly, and requires training of the experts with the software.
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None taken Khaled, I just wished to clarify the purpose of this article :) Certainly there is a lot of information to be gained from the teeth, and as you'll see later in this course, wear on Mr. X's teeth played a large role in identifying his origin from his eating habits.
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Thank you for the feedback, Anne and Shirley. Other learners have made similar comments and this has been taken on board for how to make improvements to the videos.
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Those are very sensible questions to be asking Cheryl - it makes you wonder what could have caused someone to move him after so many years, and why they chose to leave him on the waste-ground, rather than attempting to hide the body again. Perhaps they thought that after all that time he would be unidentifiable.
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Hello Khaled, this article seeks to give an introduction to identifying the sex of a skull using some of the most straightforward and prominent features. Teeth are a fairly challenging tool to identify sex as analysis focuses mainly on size, which can give the wrong impression (especially in a case like Mr X, where he was estimated to shorter than average)....
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Hi Rachel, what Mo has pointed out are very good points and can often help to make deductions about the subject's weight. What is important to remember is that a number of factors could make them unreliable, such as medical conditions or for instance if the subject had been overweight for a long time, but then lost a considerable amount in recent years, as...
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Hi Alison, that is correct, essentially what you would be referring to are known as "points of origin" and "points of insertion" for the muscles. These are the points on the bones that it is known that the muscle fibres attach to, thus allowing us to give accurate estimations of their width. The biggest challenge is in giving accurate estimations for the depth...
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Hi Jackie, what Filipe has described is very accurate - average tissue depths are used, with their specificity to the individual depending on how much evidence is present. As you'll see with the investigation for Mr X, multiple reconstructions were performed as the investigators did not have definitive evidence for Mr X's ethnicity.
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Daniel Ravenscroft replied to Alun Rees
Hello Alun, I believe an adipocerous mummy occurs when the body is stored in a COLD, moist environment. I will confirm this. Apologies for the disparity.
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Hi Laura, there are actually many more features that can be used for identifying ethnicity and sex of a skull. The articles on this course focus on the most prominent of those features, which would normally be sufficient to make an identification. An in-depth analysis could consider many more.
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Thank you all for the feedback, improvements for the videos are being considered.
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Hi Margaret, that isn't covered on the course (it's a very specific piece of information!) - but if you are interested, it is seen by small grooves on the inside of pelvic bones where remodelling has taking place after childbirth. Generally this information is more relevant to archaeological findings, as it does not offer much help in finding the identity of...
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Hi Kathleen, considering the man to have had access to medical care is a very sensible conclusion. Your following thoughts will tie in well with attempting to deduce the ethnicity of Mr X, as this could suggest where he may have received treatment.
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Hi Vicky, your point nicely addresses an important consideration in not over-committing to a certain suggestion. A key part of the forensic investigation is to provide objective findings, and as you've alluded to, this can be affected by making definitive conclusions, even if they do seem likely. You'll see more of this reflected later in the course when you...
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Hi Anne, there are actually a number of different techniques that can be used depending on the condition of the individual when found, and there is debate as to which are most effective (e.g. at removing soft tissue, without damaging the bones). These techniques are often referred to as types of 'maceration' and include things like chemical degreasing. For...
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Hello Julie, this is another reasonable suggestion giving the condition of his arm. Could you suggest why it could be difficult to trace his medical history?
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Vivienne, I do not know the specific costs of running DNA analysis but though almost all things are unfortunately run on tight budgets, DNA testing would be used when necessary - it is a highly desirable piece of evidence to use in court cases due to its reliability and objectivity. So to answer your question - for serious cases where DNA evidence would be...
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Of course, I think the video goes online today so will attempt to find a link when it does. It is only a short clip but absolutely we agree with you, a lot of the shows take some creative liberties to make them more entertaining - which is not a bad thing, but unfortunately the reality is less glamorous and far more time-consuming!
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Yes Angie that's correct, the difficulty would extend to the pelvis as well. If age is known, some inferences could be made as to sex, but these could not be made with the same degree of reliability as in adults.
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Hi Molly, myself and Daheen just filmed a short video in which we commented on the forensic techniques being used in the most recent series of Silent Witness! As you go through the course, why not think about how realistic these TV shows are.
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Exactly, it's always important in cases like these to consider that the individual may not have lived in the same country, let alone have stayed in the local area all their life. That's a good point about the screw, and combined with deduction of ethnicity may provide more information to identify Mr X.
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Hi Susan, I'm glad you enjoyed the course. Thank you for the feedback. Although it may be more useful as you learn the techniques, having completed the course you may appreciate that having such clear comparisons would not always be possible for real cases, and that often identifications would need to made from incomplete skulls.
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Hey Ramey and Patrice, you have made some very valid points here. DNA is often considered to be at the forefront of forensics as it can offer such reliable evidence towards the identity of an individual. However, there can occasionally be too much DNA damage for it to be used reliably. Even in the case of Mr X, the forensics team were able to suggest the...
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Hi Jane and Eric - two valid points here. Firstly is that yes, many of the TV shows do tend to cut some corners! Maybe you'll enjoy pointing these plot holes out with your knowledge of forensic techniques. Secondly is that the pelvis is also a very useful tool in identifying the sex of an individual. Both require analysis of several features to make a reliable...
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Certainly this could cause confusion. This is why it is important to consider many features of the skeleton (there plenty more features of the skull than are covered in this course, for instance) in trying to ascertain the sex of the individual. Other bones such as the pelvis are often preferred for this reason.
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That sounds like a very interesting course! Hopefully along with some additional introduction to forensic techniques, this course will also take you step by step through the particularly challenging case of Mr X, and how information gleaned from the forensic work was crucial in solving the case.
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Hi Tania, this is a good suggestion and one shared by many people in the discussion. Could you think of any reasons that it could be difficult to trace records of his treatments?
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There are actually many more features of the skull than are shown here (and then of the pelvis and other bones in the body) that can be used to help determine sex. So in analysing an individual who seems to have features that are difficult to distinguish, over the course of analysing all of these features a clear trend should still appear. In extreme cases...
