When is an intervening line‐up most likely to affect eyewitness identification accuracy?

Purpose. Intervening line‐ups affect identification accuracy in subsequent line‐ups. We conducted 3 experiments to investigate the conditions under which viewing multiple line‐ups is more likely to affect eyewitness identification accuracy. Method. In each of the 3 experiments, a forensically relevant factor known to affect the accuracy of face recognition memory was manipulated to assess how the factor impacted the suggestive influence of an intervening line‐up on eyewitness identification accuracy in a subsequent test line‐up. These factors were (a) in Experiment 1, same‐race versus cross race target faces, (b) in Experiment 2, whether the intervening line‐up occurred on the day of the presentation phase (close to presentation) or 1 month later on the day of the subsequent test line‐up (far from presentation), and (c) in Experiment 3, whether the target face was presented for 10 seconds or 60 seconds. Results. In each experiment, factors associated with poorer memory for the target face led to a greater suggestive influence of the intervening line‐up on identification accuracy in the subsequent line‐up, evidenced by lower hit rates and higher false‐alarm rates. Conclusions. These findings suggest that the problem of decreased identification accuracy following the viewing of an intervening photograph is especially of concern when memory for the perpetrator is likely to be poor. Implications of these findings for interpreting line‐up results in the courtroom are discussed.     

Personal identification based on radiographic vertebral features

Personal identification of human remains constitutes about 10% of the normal caseload of any forensic medicine practice. Identification can be achieved by a variety of methods, one of which is the comparison of antemortem and postmortem radiographs. There are numerous accounts of cranial and dental radiographic features useful for identification, whereas the availability of postcranial radiographs and especially plates that depict the vertebral column is less widespread among the forensic community. The authors here review the various vertebral features instrumental in positive identification that can be identified on radiographs of the spine.     

Comparative dental radiographic identification using flat panel CT

A skull without lower jaw was found and brought in for identification. It was suspected to be that of a man reported missing five years ago. An undated antemortal dental chart and two dental films of the 1st and 2nd dental quadrants, both taken about 4 years before the man went missing, were available for comparison. The method of choice in solving the identity question was comparative dental radiography. Despite numerous attempts, it was not possible to obtain radiographs of the upper jaw that duplicated the X-ray beam angulation of the antemortem dental films. The skull was thus scanned with a multislice computed tomography (MSCT) scanner, and virtual radiographs with the desired angulation were generated from the data with the maximum intensity projection (MIP) technique. The resulting virtual radiographs could, however, not be used for superimposition with the antemortem radiographs because of their poor resolution and the occurrence of artifacts caused by metallic dental fillings. The upper jaw was therefore scanned again, this time with a high resolution eLU-CT (eXplore Locus Ultra flat panel CT). The resulting eLU-CT datasets were visualized with the MIP technique and yielded virtual radiographs that could be compared with the antemortem radiographs. Positive identification could be assumed with near certainty after dental features could be matched in the superimposition of antemortem and postmortem radiographs. In the presented case, eLU-CT was used for the first time for a comparative dental radiographic identification.     

Evaluation of dental radiographic identification: an experimental study

The object of this study was to assess the value of dental radiographs for the purposes of personal identification in the absence of tooth restorations. 198 periapical and bitewing radio graphs were taken of teeth contained in 22 dry skulls obtained from the skull collection of the Royal College of Surgeons of Edinburgh. Each selected view was taken three times: by a scientist, a dentist and a dental radiographer. Each operator independently positioned the films, selected the exposure times and positioned the cone of the X-ray machine. Three groups comprising forensic odontologists, dental vocational trainees and dental trainee hygienists attempted to match the randomly mixed radiographs into sets of three. Success rates for matching radio graphs ranged from 63.6 to 100%. The average for forensic odontologists was 93.3%, vocational trainees 85.2% and hygienists 89.7%. Where forensic odontologists had both formal training and experience, or extensive experience without formal training, the success rate was 100%. Where there was formal training but little experience the success rate was lower. Participants believed that root morphology and alignment had been the greatest aid to matching and not crown morphology. The depth of knowledge of the viewer correlated poorly with the number of correct results, although the forensic odontologists achieved the highest success rate. Formal training, although highly desirable, is no substitute for practical experience. Root morphology and alignment were cited most frequently as facilitating matching.     

Personal identification by radiographic comparison of vascular groove patterns of the calvarium

A case of forensic identification utilizing the vascular grooves within the skull is presented. The case is unique in that the antemortem radiographs were from childhood, rendering useless the more standard points of comparison. Calvarial vascular grooves represent unique points of comparison when the only available premortem radiographs were obtained during childhood, especially when one is attempting to identify children (living or dead).     

Confidence and accuracy of eyewitness identification from lineups

Recent studies of confidence-accuracy correlations in eyewitness-identification experiments have produced highly variable results (Deffenbacher, 1980; Wells & Murray, 1984) with some correlations near 0 (Malpass & Devine, 1981) and others as high as 0.5 (Brigham et al., 1982). Much of this variability may be accounted for by differences, in the design of the research. Specifically, lineup experiments in which the to-be-identified person (target) is always present tend to produce higher confidence-accuracy correlations than studies also providing blank or target-absent lineups replacing the target with a lookalike. A reanalysis of previously collected data (Lindsay & Wells, 1980; Wallbridge & Lindsay, 1982) revealed that lineup foils (nontargets) were identified with significantly less confidence than targets or lookalikes but that targets and lookalikes were identified with equal confidence. Two experiments were conducted to test the hypothesis that confidence of identification is a function of the similarity of the identified person to the original target. The first experiment using nonstudent subjects (n=53) and multiple targets (n=14) to increase generalizability, demonstrated that the person in the lineup who most closely resembled the target was identified with the highest mean level of confidence. The second experiment examined confidence in identification following a crime staged for 260 introductory psychology students. The results indicated that the similarity of foils to the target (established by independent ratings) was predictive of both the frequency and confidence of identification of faces.     

The accuracy of three methods of age estimation using radiographic measurements of developing teeth

The accuracy of age estimation using three quantitative methods of developing permanent teeth was investigated. These were M?rnstad et al. [Scand. J. Dent. Res. 102 (1994) 137], Liversidge and Molleson [J. For. Sci. 44 (1999) 917] and Carels et al. [J. Biol. Bucc. 19 (1991) 297]. The sample consisted of 145 white Caucasian children (75 girls, 70 boys) aged between 8 and 13 years. Tooth length and apex width of mandibular canine, premolars and first and second molars were measured from orthopantomographs using a digitiser. These data were substituted into equations from the three methods and estimated age was calculated and compared to chronological age. Age was under-estimated in boys and girls using all the three methods; the mean difference between chronological and estimated ages for method I was -0.83 (standard deviation +/-0.96) years for boys and -0.67 (+/-0.76) years for girls; method II -0.79 (+/-0.93) and -0.63 (+/-0.92); method III -1.03 (+/-1.48) and -1.35 (+/-1.11) for boys and girls, respectively. Further analysis of age cohorts, found the most accurate method to be method I for the age group 8.00-8.99 years where age could be predicted to 0.14+/-0.44 years (boys) and 0.10+/-0.32 years (girls). Accuracy was greater for younger children compared to older children and this decreased with age.     

PCR扩增体系的体积减少对DNA分析的影响

目的探讨PCR扩增体系的体积减少对DNA分析的影响。方法4份样品采用ProfilerPlus试剂盒,在同样条件下,对50μl、25μl、12.5μl、6.25μl四种体积的体系进行扩增,扩增产物分别经ABIPRISMTM310型基因分析仪、ABIPRISMTM377型测序仪、ABIPRISMTM3100型基因分析仪电泳,并经GeneScan3.1基因扫描软件和Genotyper2.5分析软件分析得到实验结果。结果小体积的扩增体系容易出现等位基因的丢失、额外等位基因的产生等现象。结论在检材情况较差时,应该慎用小体积的扩增体系。     

Digital dental radiographic identification in the pediatric, mixed and permanent dentitions.

The purpose of this paper is to investigate the utility of digital dental radiographic superimposition in the various stages of development of the human dentition. Digital, computer assisted dental identification is a means of identification which allows the spatial relationships of the root and support structures of the teeth to be compared one to the other. The technique has not been tested in patients with developing dentitions. Dental radiographs from patients in the pediatric, mixed and permanent dentition stages of development, simulating "antemortem" and "postmortem" radiographs, were digitized using a flat field radiograph scanner. Anatomic features were used as points of comparison utilizing image editing software whereby anatomic sections were digitally cut from the antemortem image and compared to the same anatomic locations on the postmortem image to assess for points of concordance. The technique was applied to 25 cases within the primary dentition, 25 cases within the mixed dentition and 25 cases within the permanent dentition. Results showed that this was a viable technique within both the pediatric and permanent dentition although it was of little value within the mixed dentition.     

Anthropological and radiographic comparison of vertebrae for identification of decomposed human remains

This case study demonstrates the importance of involving an anthropologist in forensic situations with decomposed remains. Anthropological consultation was used in conjunction with the comparison of antemortem and postmortem radiographs to establish positive identification of unknown, decomposed remains. The remains had no traditional identifying features such as fingerprints or dental. Through anthropological analysis, it was determined the decedent was male, between 20 and 23 years at time of death and c. 5'2' tall. This information allowed for a presumptive identification and a request for antemortem radiographs. The missing person was identified comparing the spinous processes of the cervical and thoracic vertebrae between ante- and postmortem radiographs.     

The accuracy of sex identification in European skeletal remains using the phenice characters

Three documented European skeletal series were examined to assess the accuracy and reliability of the pubic variables described by Phenice for correctly identifying the sex of adult human skeletal remains. The accuracy and objectivity of these variables, as reported by Phenice, Kelley, Sutherland and Suchey, and Lovell, could not be confirmed on this European material. In general, the subpubic concavity feature, when used alone, proved to be the most reliable variable for sex identification. In this study, the level of correct sex identification that could be achieved using the Phenice variables was shown to be significantly affected by the previous experience of the observer.     

Dental identification by comparison of antemortem and postmortem dental radiographs: influence of operator qualifications and cognitive bias

Dental forensic identifications based on comparison of antemortem and postmortem radiographs provide effective and reliable evidence. There are no standardized procedures for assessing similarities between different types of dental radiographs (e.g. orthopantomograms, bitewings, and periapical radiographs), and the operator's subjective judgment can considerably affect identification. The purpose of this study is to evaluate the potential influence of experts' qualifications, training, and cognitive bias on the accuracy of identification. Seventy-eight differently qualified and experienced experts underwent an identification test. The expert sample was composed of 10 specialists in emergency care (ER), 10 specialists in legal medicine (ML), 20 pregraduate dental students (STU), 12 dentists (DENT), 20 dentists educated in forensic odontology (DENT-TRA), and 6 experienced forensic odontologists (FOR). The simulated cases required participants to assess the possible matching of 42 postmortem intraoral radiographs with 16 antemortem panoramic radiographs. Accuracy and specificity for the different operator groups were as follows: ER, 0.76-0.70; ML, 0.76-0.88; STU, 0.89-0.82; DENT, 0.87-0.97; DENT-TRA, 0.88-0.92; and FOR, 0.97-1. As evidenced by high rates of accuracy and repeatability, the most experienced forensic odontologist consistently outperformed operators less or differently educated and trained, especially for difficult cases. In our sample, the dentists who received additional education in forensic odontology did not necessarily perform better than dentists who had not received this additional education. Some cognitive bias, mainly the so-called observer effect, emerged as a possible source of outcome variability among the operator groups.     

Effect of photoarray exposure duration on eyewitness identification accuracy and processing strategy

In this study all offenders admitted to Icelandic prisons over a one year period were approached and 229 (95%) agreed to co-operate with the study. Twenty-seven (12%) of the 229 subjects claimed to have in the past made a false confession during police interviewing. Women prisoners more commonly claimed to have made a false confession than males. The main motives given for having made the false confession were to protect somebody else (48%) and police pressure or escape from custody (52%). The great majority (78%) of the subjects had never retracted the confession, claiming that they had perceived no point in dong so. Twenty-one (78%) of the subjects were convicted of the offenses to which they had, allegedly, made a false confession. The findings in the present study raise the possibility that within an inquisitorial system false confessions may go relatively undetected by the judiciary and be rarely retracted or disputed.     

中国四川省汉族人群额窦CR片的同一认定

目的研究不同投照体位CR片上额窦用于同一认定的观测指标,以编制特异的识别编码.方法用两宽度比值与形态学描述相结合的方法观测额窦CR片,并采用描述性研究方法进行描述性研究和统计分析.结果以额窦不对称性AI、额窦与眼眶宽度之比RI、最大额窦宽度的侧别、额窦上缘弓形弯曲数目(左侧、右侧)、额窦部分隔数目(左侧、右侧)、额窦中间隔位置等8项指标,编制8位数字的额窦构型同一认定编码;额窦形态性别差异无统计学意义(P＞0.05).结论额窦形态高度个人特异,可以用于同一认定,但不能用作性别判断.     

Perspectives on the impact of lineup composition,race, and witness confidence on identification accuracy

This paper addresses a number of issues suggested by the Lindsay and Wells (1980) study on lineup composition and identification accuracy. The interaction between bias in instructions to the witness, presence or absence of the criminal from the lineup, and similarity between the suspect and the lineup foils are discussed. Although Lindsay and Wells suggest that witness confidence has little or no relationship to witness accuracy, it is pointed out that a recent field study found a substantial accuracy-confidence relationship when criminal-present photo lineups were used. There are not yet clearcut findings on the accuracy-confidence relationship in criminal-absent lineups, partially because of ambiguity in the definition of confidence in this situation. Although there is much research on the impact of the race of suspect and witness on identification accuracy, little attention has been paid to the race of the person who constructs the photo or corporeal lineup. Recent research results lead to the prediction of an interaction between all three of these factors on identification accuracy, with greatest accuracy when the lineup constructor and lineup members are of the same race and the witness is of a different race. Issues in the applicability of the results of Bayesian analyses to the judicial system are briefly discussed. Potential issues include the tendency to see researchers solely as advocates for the defense, and the tendency of people to disregard statistical summaries such as base rate data and research results when making individual decisions. An additional issue concerns Bayesian diagnosticity ratios (derived from rates of correct and false identifications) which can be logically and statistically equivalent to one another but differ considerably in their legal applications and value relevance.     

Skeletal identification by radiographic comparison: blind tests of a morphoscopic method using antemortem chest radiographs

This study investigated the value of antemortem (AM) and postmortem (PM) radiographs of the claviculae and C3-T4 vertebrae to identify skeletons of missing U.S. soldiers from past military operations. In total, 12 field-recovered skeletons and AM chest radiographs of 1460 individuals were used. For each skeleton, examiners analyzed an array of AM chest radiographs (up to 1000 individuals) and attempted to identify the correct PM/AM radiographic match. When examiners were able to compare all images within a single test, only true-positive identifications were made. When AM radiographs were presented one-at-a-time, in sequential order, and without examiners having knowledge of array size, erroneous identifications resulted but they were almost exclusively made by untrained examiners (accuracy = 35% vs. 90% for trained examiners). This study demonstrates the value of chest radiographs for the identification of disarticulated and even eroded skeletons, but only when methods are wielded by trained examiners.