米国におけるタナー法の評価

　浅田古稀の吉井論文に紹介されていたもの
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Misuse of Tanner Puberty Stages to Estimate Chronologic Age
Arlan L. Rosenbloom, James M. Tanner
https://www.researchgate.net/publication/13407242_Misuse_of_Tanner_Puberty_Stages_to_Estimate_Chronologic_Age

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Forensic Sci Int. 2009 Jan 10;183(1-3):e21-4. doi: 10.1016/j.forsciint.2008.09.005. Epub 2008 Nov 18.
The difficult issue of age assessment on pedo-pornographic material.

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Int J Legal Med. 2013 Mar;127(2):467-71. doi: 10.1007/s00414-012-0765-8. Epub 2012 Sep 8.
Inaccuracy of age assessment from images of postpubescent subjects in cases of alleged child pornography.
Rosenbloom AL1.

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Child porn evidence unreliable: study of Playboy
http://www.reuters.com/article/us-child-porn-idUSBRE88202J20120903

以下は、奥村が外国の文献を検索してみた結果

Child Pornography: Law and Policy

Alisdair A. Gillespie　Child Pornography: Law and Policy
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One of the difficulties in providing expert testimony is in respect of agreeing what thebasis for the expertise is. Many experts use Tanner staging to identify the age of a child(Cattaneo et al., 2009: e22). The Tanner staging method describes the different stages ofsexual maturation and can be used to map pubertal development but it has been statedthat Tanner himself suggests that using the Tanner stages to identify the chronologicalage of a child is illegitimate (Cattaneo et al., 2009: e22). This is because pubertaldevelopment is different for each individual and depends on a number of factors.Accordingly ascertaining age through pubertal development would be problematicalthough there is some evidence to suggest that in jurisdictions that do allow expertevidence, this is one of the methods used (Lueher, 2005: 15).Few studies have been conducted on the reliability of ascertaining age but aninteresting study was conducted by Cattaneo et al. (2009). This study specificallyaddresses the issue about whether lay persons are any better than experts at ascertainingage. The experts used were forensic pathologists, paediatricians and gynaecologists, allpeople that would be expected to be familiar with methods of aging children. Theassessment was relatively crude in that the participants were shown eleven photographsof nude women (all of which were aged over 18). The participants were asked tosimply decide whether a person was aged above or below 18. The stark conclusion ofthe study is that no category did particularly well at identifying age. Forensicpsychologists performed best but they correctly identified age in only 55 per cent ofcases (Cattaneo et al., 2009: e22–e23). In other words they got almost as many wrongas they did right. Lay persons correctly identified age in 37 per cent of cases and inItaly they correctly identified them in 50 per cent of cases. Paediatricians were worst atidentifying age, with the study showing that they were wrong up to 95 per cent of thetime.Of course a weakness with the Cattaneo study is that it focused simply on the age of18 and so it does not suggest that, for example, a person would not recognise a prepubescentindividual as a child. However in such cases the age of a child would neverbe in doubt (save for issues of sentencing). The cases where age is relevant are wherethere is doubt as to whether a child (who may be well developed in terms of postpubertysexual physiology) is above the age of 18. The Cattaneo study suggests thatneither lay persons nor experts were particularly good at identifying whether a personwas aged above or below 18. To an extent it can be argued therefore that the Court ofAppeal was right in Land to suggest that expert evidence would not be of assistancesince the experts could be equally wrong.The findings of the study do raise significant questions in respect of the prosecutionof child pornography. The difficulty in ascertaining age has led some to note that lawenforcement agencies will be slow to tackle ‘borderline’ images (Wells et al., 2007:276). This is something that will be considered in Chapter 12 but the position inEngland and Wales is complicated slightly by the fact that age is relevant to thesentencing of offenders. This is something that will be discussed in Chapter 10 but itdoes mean identifying the broad age of a child can be necessary.
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There are no clear rules on how the expert should gauge the age of a child. In manyreported cases the prosecution call a medically qualified practitioner who uses the‘Tanner scale’ to identify children (a useful summary of the practice of the Sixth Circuitis presented in US v Noda 137 Fed Appx 856 (2005) at 864). The ‘tanner scale’evaluates the progression of a person through the stages of puberty. It is possible tocompare this to the ‘typical’ pubertal development of a child to estimate the agealthough Cattaneo et al. have suggested this use is controversial and note that thedeveloper of the Tanner Scale has argued that using the scale to provide expertevidence as to age is ‘wholly illegitimate’ (Cattaneo et al., 2009: e22). That said, themere fact that the person who develops a system disagrees with its use cannot beconclusive as it is possible that other, equally qualified persons, can show that it can beused in this modified way.Since an expert is simply putting forward his or her expert opinion, the reliability ofthe methodology they used to arrive at this opinion is something that can be put to theexpert in cross-examination. Accordingly, for example, where they use the Tanner Scaleand the defendant believes that this use is inappropriate or has led to a false result thenthose questions can be put to the witness during the trial (see the discussion in US vHamilton 413 F.3d 1138 (2005) at pp. 1143.1144). The tribunal of fact can decidewhat weight (if any) to place on this expert evidence and can, in any event, make theirown opinion on the matter from seeing the material (US v Rayl 270 F.3d 709 at 714)and decide whether the prosecution have proven, beyond all reasonable doubt, that theperson depicted is under the age of 18.

Child Pornography Legal and Medical Considerations
http://www.advancesinpediatrics.com/article/S0065-3101(09)00003-6/abstract
Ethnic considerations in pubertal development
In looking at a photograph, the assessor will comment on the degree of sexual maturity, and then attempt to assign an age based on secondary sexual characteristics if present, while taking into account other morphologic findings. Assigning an age to an individual is therefore contingent on information regarding the age of pubertal development in that individual’s population or racial or ethnic group. There have been numerous studies over the past 40 years examining the age of puberty in different parts of the world [26–70]. Stathopulu and colleagues [7], using a review of the literature, examined the average age of menarche in girls from Southeast Asia. Variation in the age of menarche was associated with factors such as socioeconomic status, maternal nutrition during pregnancy, and nutrition during childhood. Age of onset of pubertal development was more difficult to assess, and variability was noted. It appeared that at least 10% of Chinese girls had achieved an SMR of 2 for breast development (B2) before the age of 8 years. The investigators also noted that the secular trend for earlier onset of menarche had slowed down. The median age of menarche in London, England in 1969 was 13.0 years; by 1999, the age was 12.9 years, younger, though significantly not different when determining the age of girls in pornographic photographs. Overall, the investigators concluded that 97.5% of Southeast Asian girls achieve B2 breast development by age 13.7, and if breast development was below B2, one could conclude with 97.5% certainty that the individual was under that age (ie, younger than 13.7 years). There is now a plethora of studies addressing the age of menarche throughout the world, and though there are some differences, the mean age of menarche seems to be about 12.2 1.2 years [66]. The impact of other health considerations has been noted in some studies. Abolfotouh [71] reported a delay in pubertal maturation in blind and deaf male students in Saudi Arabia. He specifically noted that only 79% of blind students and 70% of deaf students had achieved a sexual maturity rating of 4 or 5 by age 16 years. There were no comparison groups of normally sighted or hearing students to observe how divergent this was from the ethnic population with which he was working. Abolfotouh concludes, however, that blind and deaf children attain sexual maturity at an older age than the reference population. Although there are some data suggesting a further decrease in the age of puberty in the United States in recent years, the trend seems to be toward earlier breast development but not menarche, and this trend may be related to the increasing incidence of child hood obesity [72]. From a forensic perspective, a trend toward earlier puberty would lead to an overestimation of the age of children in the images, rather than an underestimation (eg, estimating a 9-year-old girl with B4 to be 16 years old). In 1998, Rosenbloom and Tanner [73], in a letter published in Pediatrics, criticized the practice of assigning age-based sexual maturity rating as an ‘‘illegitimate use’’ of the data. Detective James F. McLaughlin [74], in a letter to Dr Rosenbloom, noted that experts did not use the Tanner Scale in isolation but rather in the context of rendering an expert opinion based on ‘‘knowledge, skill, experience, training, or education.’’ Rosenbloom responded to Detective McLaughlin that indeed such assessments were not simply related to Tanner rating [75]. The California Court of Appeals, in People v Thomas Joseph Kurey, determined that testimony regarding age using the Tanner scale was admissible [76]. Defense attorneys, however, continue to use the 1998 letter of Tanner and Rosenbloom to question the validity of the age assignment, and expert consultants should therefore be familiar with both the medical literature and the legal opinions related to these discussions. The numerous studies defining the age range of pubertal development around much of the world have to some extent addressed the criticism of Rosenbloom and Tanner, and have led to a purposeful avoidance of using the term ‘‘Tanner staging’’ and use of the replacement terms SMR or SMI, or the designation with the specific ratings B, PH, G for breast, public hair, and genitals.