Pub Date : 2024-02-21DOI: 10.1016/j.scijus.2024.02.005
Max Coleman
A new method for looking for life outside the Earth is used as an example to demonstrate how ways of presenting complex scientific concepts to the general public, used in planetary science, could be used in forensic science. The work led to a pared down, practical definition of detectable Life for planetary exploration, An organised system capable of processing energy sources to its advantage. For nearly three quarters of Earth’s history the only lifeforms were microbes, which are the target for looking for extraterrestrial life. Microbes are microscopic and may be sparsely distributed, but their metabolic products can form large, durable rocks, much easier to find and which may contain the organisms or their remains.
There are similar challenges in presenting astrobiological and forensic science. Both may have to deal with very large or very small numbers which are not immediately comprehensible but can be understood by analogy. To increase the impact on the listener or reader, dramatic analogues are valuable, for example, referring to the mineralised microbial metabolic products as, “fossilised breath of bacteria” demands the audience's attention and engages them before more detailed explanations are given. The power of practical experiments or demonstrations is most important to reinforce what might otherwise be a fairly abstract concept. Surprisingly, most of these approaches can be made to work equally well in both spoken and written forms as well as in both sciences.
{"title":"Martian microbes research and lessons learnt for forensic science","authors":"Max Coleman","doi":"10.1016/j.scijus.2024.02.005","DOIUrl":"10.1016/j.scijus.2024.02.005","url":null,"abstract":"<div><p>A new method for looking for life outside the Earth is used as an example to demonstrate how ways of presenting complex scientific concepts to the general public, used in planetary science, could be used in forensic science. The work led to a pared down, practical definition of detectable Life for planetary exploration, <em>An organised system capable of processing energy sources to its advantage.</em> For nearly three quarters of Earth’s history the only lifeforms were microbes, which are the target for looking for extraterrestrial life. Microbes are microscopic and may be sparsely distributed, but their metabolic products can form large, durable rocks, much easier to find and which may contain the organisms or their remains.</p><p>There are similar challenges in presenting astrobiological and forensic science. Both may have to deal with very large or very small numbers which are not immediately comprehensible but can be understood by analogy. To increase the impact on the listener or reader, dramatic analogues are valuable, for example, referring to the mineralised microbial metabolic products as, “fossilised breath of bacteria” demands the audience's attention and engages them before more detailed explanations are given. The power of practical experiments or demonstrations is most important to reinforce what might otherwise be a fairly abstract concept. Surprisingly, most of these approaches can be made to work equally well in both spoken and written forms as well as in both sciences.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 3","pages":"Pages 251-257"},"PeriodicalIF":1.9,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139927750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In forensic paint examination, paint traces retrieved on a crime scene are regularly compared to painted objects seized from a suspect. Less often, traces are only observed on the seized objects and compared to a damaged painted object on the crime scene. In some specific cases, paint traces may be found both on the crime scene and on one or multiple seized painted objects. The latter may be the result of a cross-transfer that occurred during the illicit act. However, mere coincidence is another possible explanation for these observations and may not be neglected. Proper consideration of the relevant populations and sufficient analytical data permits the evaluation of the results given activity level propositions. This allows the forensic expert to present a transparent and well-balanced statement on the value of their findings concerning the disputed issues in court.
{"title":"Interpretation of a paint cross-transfer on a burglary scene – A case report","authors":"Florian Vanneste , Yu Chen Lim-Hitchings , Geneviève Massonnet , Kyra Lunstroot","doi":"10.1016/j.scijus.2024.02.004","DOIUrl":"10.1016/j.scijus.2024.02.004","url":null,"abstract":"<div><p>In forensic paint examination, paint traces retrieved on a crime scene are regularly compared to painted objects seized from a suspect. Less often, traces are only observed on the seized objects and compared to a damaged painted object on the crime scene. In some specific cases, paint traces may be found both on the crime scene and on one or multiple seized painted objects. The latter may be the result of a cross-transfer that occurred during the illicit act. However, mere coincidence is another possible explanation for these observations and may not be neglected. Proper consideration of the relevant populations and sufficient analytical data permits the evaluation of the results given activity level propositions. This allows the forensic expert to present a transparent and well-balanced statement on the value of their findings concerning the disputed issues in court.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 3","pages":"Pages 258-263"},"PeriodicalIF":1.9,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139927640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-13DOI: 10.1016/j.scijus.2024.02.003
Ashraf Mashaly , Mohammed S. Al-Khalifa
This article investigates a critical part of professional careers: adhering to a code of ethics that defines proper behavior within the context of one's specialized practice. It aims to improve the setting of forensic entomology work by highlighting the ethical issues that frequently emerge. The primary goal is to uncover common ethical issues involved in this field's everyday activities and provide informed advice on appropriate resolution options. This investigation dives into the complex interaction of religious beliefs, cultural aspects, and issues of ethics, evaluating their relevance in forensic entomology. It examines a wide range of ethical issues, from the ethics involved in collecting samples at crime scenes and morgues to the ethics created into scientific investigations, report writing, and court testimony. These guiding principles are critical in setting scientific standards and building public trust in forensic entomology's ability to provide exceptional services. Notably, regardless of whether the forensic entomology service provider is accredited by any validating organization, these ethical requirements remain critical, emphasizing their global application.
{"title":"Exploring the ethical dimensions in forensic entomology: From codes of conduct to professional accountability","authors":"Ashraf Mashaly , Mohammed S. Al-Khalifa","doi":"10.1016/j.scijus.2024.02.003","DOIUrl":"10.1016/j.scijus.2024.02.003","url":null,"abstract":"<div><p>This article investigates a critical part of professional careers: adhering to a code of ethics that defines proper behavior within the context of one's specialized practice. It aims to improve the setting of forensic entomology work by highlighting the ethical issues that frequently emerge. The primary goal is to uncover common ethical issues involved in this field's everyday activities and provide informed advice on appropriate resolution options. This investigation dives into the complex interaction of religious beliefs, cultural aspects, and issues of ethics, evaluating their relevance in forensic entomology. It examines a wide range of ethical issues, from the ethics involved in collecting samples at crime scenes and morgues<!--> <!-->to the ethics created into scientific investigations, report writing, and court testimony. These guiding principles are critical in setting scientific standards and building public trust in forensic entomology's ability to provide exceptional services. Notably, regardless of whether the forensic entomology service provider is accredited by any validating organization, these ethical requirements remain critical, emphasizing their global application.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 2","pages":"Pages 243-249"},"PeriodicalIF":1.9,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139879628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-12DOI: 10.1016/j.scijus.2024.02.002
Laura Donato , Douglas H. Ubelaker , Luigi Marsella , Maryana Munyendo , Michele Treglia , Jessika Camatti , Sara Dagoli , Rossana Cecchi
The age progression technique allows to update identification photos of individuals who have been missing for years. This method is based on the study of the facial variation and on the dynamics of facial growth. Knowledge about changes in the distribution of facial fat and the tone of the cartilage allows realistic predictions of the facial appearance after many years. Beside these elements, age progression is also supported by similar characters between family members. This is why photos of the missing and family members are used to create an age progression, making the new identikit accurate.
Non-profit associations are crucial for the dissemination of information on the problem of missing persons. In Italy, the Italian Missing Children association provides for free an age progression service with the support of forensic anthropology. With the activation of a protocol, consisting of guidelines, and a form for the request for age progression by family members, the Italian Missing Children has started a collaboration with Missing Child Kenya. It allowed to disseminate up-to-date photos of the presumed current appearance of the missing children in Kenya. Thus, in the present study some cases are reported, in which age progression technique was applied.
The photos provided by Italian Missing Children were shown in video documentaries made by Missing Child Kenya, allowing to continue the dissemination of age progression photo during the Covid quarantines and to keep the population active in the search for the missing.
{"title":"The forensic imaging technique of age progression used within missing people cases: The Italian Missing Children association realizing age progression for Missing Child Kenya","authors":"Laura Donato , Douglas H. Ubelaker , Luigi Marsella , Maryana Munyendo , Michele Treglia , Jessika Camatti , Sara Dagoli , Rossana Cecchi","doi":"10.1016/j.scijus.2024.02.002","DOIUrl":"https://doi.org/10.1016/j.scijus.2024.02.002","url":null,"abstract":"<div><p>The age progression technique allows to update identification photos of individuals who have been missing for years. This method is based on the study of the facial variation and on the dynamics of facial growth. Knowledge about changes in the distribution of facial fat and the tone of the cartilage allows realistic predictions of the facial appearance after many years. Beside these elements, age progression is also supported by similar characters between family members. This is why photos of the missing and family members are used to create an age progression, making the new identikit accurate.</p><p>Non-profit associations are crucial for the dissemination of information on the problem of missing persons. In Italy, the Italian Missing Children association provides for free an age progression service with the support of forensic anthropology. With the activation of a protocol, consisting of guidelines, and a form for the request for age progression by family members, the Italian Missing Children has started a collaboration with Missing Child Kenya. It allowed to disseminate up-to-date photos of the presumed current appearance of the missing children in Kenya. Thus, in the present study some cases are reported, in which age progression technique was applied.</p><p>The photos provided by Italian Missing Children were shown in video documentaries made by Missing Child Kenya, allowing to continue the dissemination of age progression photo during the Covid quarantines and to keep the population active in the search for the missing.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 2","pages":"Pages 210-215"},"PeriodicalIF":1.9,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139732635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-10DOI: 10.1016/j.scijus.2024.02.001
Georgina E. Meakin , Guilherme S. Jacques , Ruth M. Morgan
Items of worn clothing are routinely examined for DNA in forensic casework, commonly with the expectation that at least some of the DNA will come from a wearer of the item, so-called ‘wearer DNA’. This study investigated DNA recovered from hooded jumpers that were regularly worn and laundered for four weeks and then subsequently worn by a different individual for four hours. This study also systematically investigated whether using different recovery methods or sampling locations on the jumpers might distinguish between DNA deposited by the regular and most recent wearers of clothing. Four volunteers each wore a new hooded jumper regularly (6 h/day, 2 days/week, washed at weekends) during two 4-week periods. At the end of each month, DNA was first recovered by cutting out and mini-taping the inside left cuff, half-collar, pocket and underarm fabric. The jumpers were then worn by a different individual for four hours, and DNA was again recovered by cutting out and mini-taping, but this time from the inside right cuff, half-collar, pocket and underarm fabric. All DNA samples (n = 128) were quantified and profiled. DNA quantities ranged from 0 to ∼40 ng with an outlier of ∼150 ng, and no significant differences were observed among recovery methods and sampling locations, nor whether one or two wearers had worn the jumpers. However, one volunteer consistently deposited significantly more DNA to their jumpers than two other volunteers, confirming the impact of ‘shedder status’ on DNA deposition during wearing of clothing. When jumpers were regularly worn by one wearer, the majority (72.7–83.3 %) of the samples for all wearers across both months comprised a major profile of the wearer with a minor profile of non-wearer alleles. When jumpers were then worn by a second wearer, the composition of the profiles obtained were generally reproducible across the recovery methods used, the sampling locations and the two replicates of the experiment for each pairing of wearers. However, profile compositions differed between wearer pairings. Overall, ∼60 % of profiles obtained gave a major profile of the regular wearer, whereas ∼30 % gave a major profile of the second wearer. The remaining profiles comprised other much less frequent observations of single-source profiles of each wearer and equal proportions of DNA from both wearers. Non-wearer DNA was also observed in the majority of samples, both before and after jumpers were worn by a second wearer. For one volunteer’s jumpers, a recurring non-wearer DNA profile was observed that could be attributed to their romantic partner, and this DNA persisted on the jumpers even after being worn by the second wearer. This study provides insight on the impact of shedder status, multiple wearers, different recovery methods and sampling locations on the quantities of DNA and compositions of DNA profiles recovered from authentically regularly-worn hooded jumpers. The findings also provide a preliminary dataset that can
在法医办案过程中,通常会对穿过的衣物进行 DNA 检测,预计至少有部分 DNA 来自于衣物的穿着者,即所谓的 "穿着者 DNA"。本研究调查了从连帽式连身衣中提取的 DNA,这些连帽式连身衣被定期穿着并清洗四周,然后由不同的人穿着四小时。这项研究还系统地调查了采用不同的回收方法或在连体衣上不同的取样位置是否可以区分衣物的经常穿着者和最近穿着者所沉积的 DNA。四名志愿者在两个为期 4 周的时间内,每人定期(每天 6 小时,每周 2 天,周末清洗)穿着一件新的连帽衫。每个月末,首先将左袖口内侧、半领、口袋和腋下的布料剪下并用小胶带粘好,以回收 DNA。然后,由不同的人穿上连体衣四小时,再次剪下并用小胶带粘贴,但这次是从右袖口内侧、半领、口袋和腋下的布料中提取DNA。对所有 DNA 样品(n = 128)进行了量化和分析。DNA数量从0到40纳克不等,离群值为150纳克,不同的回收方法和取样位置,以及是否有一个或两个穿着者穿过连体衣,都没有发现明显的差异。然而,一名志愿者的连体衣上的DNA沉积量一直明显高于其他两名志愿者,这证实了 "脱落者身份 "对穿衣时DNA沉积的影响。当一名穿着者经常穿着连体衣时,两个月中所有穿着者的大部分样本(72.7%-83.3%)都是由穿着者的主要等位基因和非穿着者的次要等位基因组成的。当第二位穿着者再穿连体衣时,在每对穿着者使用的回收方法、取样地点和两个重复实验中,所获得的等位基因谱组成基本一致。不过,不同配对佩戴者的轮廓组成也不尽相同。总体而言,60%的特征描述以正常穿戴者为主要特征,30%的特征描述以第二位穿戴者为主要特征。其余的图谱中,每个穿戴者的单一来源图谱和来自两个穿戴者的相同比例 DNA 的观察次数要少得多。在大多数样本中还观察到了非穿着者的 DNA,无论是在第二位穿着者穿着连体衣之前还是之后。在一名志愿者的连体衣上,反复观察到了非穿着者的 DNA 图谱,这可能是他们的恋爱伴侣所为,即使在第二名穿着者穿着连体衣后,这种 DNA 在连体衣上依然存在。这项研究深入探讨了脱落者身份、多次穿戴者、不同的回收方法和取样地点对从真正定期穿戴的连帽衫中回收的DNA数量和DNA图谱组成的影响。研究结果还提供了一个初步数据集,可用于推断案件工作中的活动水平概率。
{"title":"Comparison of DNA recovery methods and locations from regularly-worn hooded jumpers before and after use by a second wearer","authors":"Georgina E. Meakin , Guilherme S. Jacques , Ruth M. Morgan","doi":"10.1016/j.scijus.2024.02.001","DOIUrl":"10.1016/j.scijus.2024.02.001","url":null,"abstract":"<div><p>Items of worn clothing are routinely examined for DNA in forensic casework, commonly with the expectation that at least some of the DNA will come from a wearer of the item, so-called ‘wearer DNA’. This study investigated DNA recovered from hooded jumpers that were regularly worn and laundered for four weeks and then subsequently worn by a different individual for four hours. This study also systematically investigated whether using different recovery methods or sampling locations on the jumpers might distinguish between DNA deposited by the regular and most recent wearers of clothing. Four volunteers each wore a new hooded jumper regularly (6 h/day, 2 days/week, washed at weekends) during two 4-week periods. At the end of each month, DNA was first recovered by cutting out and mini-taping the inside left cuff, half-collar, pocket and underarm fabric. The jumpers were then worn by a different individual for four hours, and DNA was again recovered by cutting out and mini-taping, but this time from the inside right cuff, half-collar, pocket and underarm fabric. All DNA samples (n = 128) were quantified and profiled. DNA quantities ranged from 0 to ∼40 ng with an outlier of ∼150 ng, and no significant differences were observed among recovery methods and sampling locations, nor whether one or two wearers had worn the jumpers. However, one volunteer consistently deposited significantly more DNA to their jumpers than two other volunteers, confirming the impact of ‘shedder status’ on DNA deposition during wearing of clothing. When jumpers were regularly worn by one wearer, the majority (72.7–83.3 %) of the samples for all wearers across both months comprised a major profile of the wearer with a minor profile of non-wearer alleles. When jumpers were then worn by a second wearer, the composition of the profiles obtained were generally reproducible across the recovery methods used, the sampling locations and the two replicates of the experiment for each pairing of wearers. However, profile compositions differed between wearer pairings. Overall, ∼60 % of profiles obtained gave a major profile of the regular wearer, whereas ∼30 % gave a major profile of the second wearer. The remaining profiles comprised other much less frequent observations of single-source profiles of each wearer and equal proportions of DNA from both wearers. Non-wearer DNA was also observed in the majority of samples, both before and after jumpers were worn by a second wearer. For one volunteer’s jumpers, a recurring non-wearer DNA profile was observed that could be attributed to their romantic partner, and this DNA persisted on the jumpers even after being worn by the second wearer. This study provides insight on the impact of shedder status, multiple wearers, different recovery methods and sampling locations on the quantities of DNA and compositions of DNA profiles recovered from authentically regularly-worn hooded jumpers. The findings also provide a preliminary dataset that can","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 2","pages":"Pages 232-242"},"PeriodicalIF":1.9,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1355030624000066/pdfft?md5=1885630746fce66db765519d2c89d4c9&pid=1-s2.0-S1355030624000066-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139927749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The individuality and permanence of fingerprints make of them a very useful feature in the identification of individuals. There are now automated computer programmes that allow a quick comparison between a fingermark and a database. However, in order to assess the strength of evidence in fingerprint identification, complementary information on the frequencies of the different morphological features of the dermopapillary ridges is required. This idea is used in this work as a starting point to evaluate the frequencies of the parameters used in the determination of the hand and finger in a large sample of 2600 fingerprints taken from 134 male and 127 female Spanish population. Based on these fingerprints, the frequencies of different categories of the following parameters were obtained: type of pattern, slope of the apex ridge, subtype of two-delta pattern, ridge tracing, major angle, major ridge count, bisector, rotation of the central ridge, assimilation to loops and slant. Moreover, the results have shown that these characters are useful for the determination of the hand in whorls (two-delta pattern) and loops (one-delta pattern), but not for the determination of the finger. The most useful and classificatory parameter when determining the hand of origin of a two-delta fingerprint is the slope of the apex ridge, and for the one-delta pattern, knowing the location of the delta allows the correct estimation of the hand of a fingerprint in more than 93% of the cases. The data presented in this paper are novel and can be used by latent print examiners to improve the statistical basis of their decisions in reaching conclusions.
{"title":"Study of the fingerprints of a Spanish sample for the determination of the hand and finger","authors":"Noemí Rivaldería , Ariadna Moreno-Piedra , Ainhoa Álvarez , Esperanza Gutiérrez-Redomero","doi":"10.1016/j.scijus.2024.01.005","DOIUrl":"https://doi.org/10.1016/j.scijus.2024.01.005","url":null,"abstract":"<div><p>The individuality and permanence of fingerprints make of them a very useful feature in the identification of individuals. There are now automated computer programmes that allow a quick comparison between a fingermark and a database. However, in order to assess the strength of evidence in fingerprint identification, complementary information on the frequencies of the different morphological features of the dermopapillary ridges is required. This idea is used in this work as a starting point to evaluate the frequencies of the parameters used in the determination of the hand and finger in a large sample of 2600 fingerprints taken from 134 male and 127 female Spanish population. Based on these fingerprints, the frequencies of different categories of the following parameters were obtained: type of pattern, slope of the apex ridge, subtype of two-delta pattern, ridge tracing, major angle, major ridge count, bisector, rotation of the central ridge, assimilation to loops and slant. Moreover, the results have shown that these characters are useful for the determination of the hand in whorls (two-delta pattern) and loops (one-delta pattern), but not for the determination of the finger. The most useful and classificatory parameter when determining the hand of origin of a two-delta fingerprint is the slope of the apex ridge, and for the one-delta pattern, knowing the location of the delta allows the correct estimation of the hand of a fingerprint in more than 93% of the cases. The data presented in this paper are novel and can be used by latent print examiners to improve the statistical basis of their decisions in reaching conclusions.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 2","pages":"Pages 216-231"},"PeriodicalIF":1.9,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1355030624000054/pdfft?md5=8254f34ee8d34541bf682be913ed8ad7&pid=1-s2.0-S1355030624000054-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139748768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-02DOI: 10.1016/j.scijus.2024.01.004
Francesca Spencer , Kirsten Verostick , Alejandro Serna , Chris Stantis , Gabriel J. Bowen
Isotopic analysis of human tooth enamel can provide life history information useful in forensic identification. These applications depend on the availability of reference data documenting isotopic values for individuals with known life history and on the comparability of data from reference and case work samples. Here we build on previous methodological research, which has largely focused on paleontological and archaeological samples, and conduct experiments using enamel from modern human teeth targeting three sample preparation variables (sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in particle size affect the efficiency of sample reactions during pretreatment and analysis, with coarse particles giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope values than fine particles during analysis. Data for samples stored in dry and ambient environments following pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the importance of methodological standardization to improve comparability and reduce potential for bias in the forensic application of tooth enamel isotope data.
{"title":"Effects of particle size, storage conditions, and chemical pretreatments on carbon and oxygen isotopic measurements of modern tooth enamel","authors":"Francesca Spencer , Kirsten Verostick , Alejandro Serna , Chris Stantis , Gabriel J. Bowen","doi":"10.1016/j.scijus.2024.01.004","DOIUrl":"10.1016/j.scijus.2024.01.004","url":null,"abstract":"<div><p>Isotopic analysis of human tooth enamel can provide life history information useful in forensic identification. These applications depend on the availability of reference data documenting isotopic values for individuals with known life history and on the comparability of data from reference and case work samples. Here we build on previous methodological research, which has largely focused on paleontological and archaeological samples, and conduct experiments using enamel from modern human teeth targeting three sample preparation variables (sample particle size, storage conditions, and chemical pretreatments). Our results suggest that differences in particle size affect the efficiency of sample reactions during pretreatment and analysis, with coarse particles giving reduced loss of enamel carbonate during acid pretreatments but producing slightly higher oxygen isotope values than fine particles during analysis. Data for samples stored in dry and ambient environments following pretreatment were indistinguishable, suggesting no exchange of oxygen between samples and ambient water vapor. Finally, chemical pretreatments with a range of commonly used reactants and conditions showed a pervasive, moderate oxygen isotope shift associated with acetic acid treatment, which may be caused by exchange of enamel hydroxyl groups with reagents or rinse waters. Collectively, the results emphasize the importance of methodological standardization to improve comparability and reduce potential for bias in the forensic application of tooth enamel isotope data.</p></div>","PeriodicalId":49565,"journal":{"name":"Science & Justice","volume":"64 2","pages":"Pages 193-201"},"PeriodicalIF":1.9,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139663968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}