Two-dimensional metric comparisons between dynamic bare footprints and insole foot impressions-forensic implications

Footwear may be found at crime scenes as physical evidence. Such footwear often has impression features of the wearer’s foot on the insole of the shoe. Scientific research and literature have established that footprints are distinct. This study compares two-dimensional measurements on bare footprints to foot impressions on insoles to determine if significant differences or similarities exist. Dynamic footprints were collected from 51 donors using the Identicator® Inkless Shoe Print Model LE 25P system. Seven foot length and width measurements were taken based on the Reel linear measurement method. Footprint measurements between bare footprints and foot impressions on the insoles were compared. Only two differences (p > 0.05) were observed between the various bare footprint and insole foot impression measurements on the right and left side for most of the measurements, CALC (p < 0.001) and A1 (p = 0.04). Bare footprint and insole A5 measurements on the left side were also significantly different (p = 0.015). The results of the study have implications in the forensic analysis of foot impression evidence on insoles in footwear in assisting with identifying the wearer of said footwear. Situations may arise in the forensic context when comparing the foot impression on the insole of footwear to a suspect’s bare footprint or a footprint from post-mortem remains. This study contributes to the scant literature available on the topic and to understanding the similarities and differences observed in the various linear measurements that may be utilized in the comparison process of footprint impressions on shoe insoles to bare footprints.     

鞋内底足迹显现效果的影响因素

目的探究鞋内底足迹的显出情况及可能影响显现效果的因素,寻找有效的鞋内底足迹显现方法。方法收集PU材质的皮鞋鞋垫、EVA材质的运动鞋鞋垫、解放牌胶鞋鞋垫共144只,用多波段光源法、茚二酮法、茚三酮法三种方法分别对穿用时间为一周、一个月、三个月、六个月的鞋内底足迹进行显现,按照显现方法、材质、穿用时间进行分类讨论并对数据进行统计和分析。结果采用多波段光源法、茚二酮法、茚三酮法分别成功显出15、14、19例,有效显出率分别为31.25%、29.17%、39.58%,PU材质、EVA材质、解放牌胶鞋三种材质分别成功显出15、23、10例,有效显出率分别为31.25%、47.92%、20.83%,穿用时间为一周、一个月、三个月、六个月的检材分别成功显出3、6、13、26例,有效显出率分别为8.33%、16.67%、36.11%、72.22%。多波段光源法、茚二酮法、茚三酮法对鞋内底足迹显出率的影响,其差异无明显统计学意义;EVA材质运动鞋鞋内底足迹显出率高于PU材质皮鞋鞋内底足迹显出率,高于解放牌胶鞋鞋内底足迹显出率,并且差异具有统计学意义;穿用时间长的检材显出率高于穿用时间短的检材并且差异具有统计学意义。结论鞋内底足迹的显现效果与鞋内底材质、穿用时间因素有关,多波段光源法、茚二酮法、茚三酮法均能对鞋内底足迹有效显出。     

Application of non-contact scanning to forensic podiatry: A feasibility study

Foot impression evidence recovered from crime scenes can be available in the form of barefoot prints, sock-clad footprints, or as impressions within footwear. In some cases, suspects leave their footwear at the scene of the crime, and the insoles from the footwear can be important in linking a person to the footwear. The application of 3D data-collecting technology is becoming more and more popular within forensic science and has been used to recover footwear impression evidence. The present study is a feasibility study to discover if 3D data capturing devices can be applied to insoles; to capture the footprint impression for measurement using the Gunn method (a method used in forensic podiatry casework). Three different methods of data capture were conducted; Adobe Photoshop, MeshLab, and calipers used directly on the insole. Paired t-tests and Intraclass Correlation Coefficient (ICC) were conducted for all three data capture methods. Seven measurements used in this study were significantly different across all three methods. ICC scores were moderate to excellent for the Photoshop method, poor to good for the 3D method, and moderate to excellent for the Direct method.     

Two-dimensional linear analysis of dynamic bare footprints: A comparison of measurement techniques

In forensic intelligence-gathering, footprints have been shown to be valued evidence found at crime scenes. Forensic podiatrists and footprint examiners use a variety of techniques for measuring footprints for comparison of the crime scene evidence with the exemplar footprints. This study examines three different techniques of obtaining two-dimensional linear measurement data of dynamic bare footprints. Dynamic bare footprints were gathered from 50 students from a podiatric medical school using the Identicator® Inkless Shoe Print Model LE 25P system. After obtaining 100 bilateral footprints from the participants, the quantitative measurement data were collected by using three different measurement techniques: (i) a manual technique using a ruler (direct technique); (ii) an Adobe® Photoshop® technique; and (iii) a GIMP (GNU Image Manipulation Program) technique. The seven Reel linear measurement methodology was used for producing measurements using these three techniques.This study showed that all the mean bare footprint measurements on the right and left feet obtained using the direct technique were larger than those obtained using GIMP and Adobe® Photoshop® images. Differences were also observed in measurements produced using GIMP software and Photoshop images. However, the differences observed in the three techniques used for bare footprint measurements were not found to be statistically significant. The study concludes that there are no significant differences between the three measurement techniques when applied to two-dimensional bare footprints using the Reel method. It further concluded that any of these measurement techniques can be used when employing the Reel methodology for footprint analysis without significant difference.     

The contact area of static and dynamic footprints: Forensic implications

When found at crime scenes, footprints may be evidentially valuable and can assist with the identity of a perpetrator based on their features and/or measurements. Footprints can be either static (made while standing) or dynamic (made while walking). While extensive research has been performed on the linear measurements obtained from static and dynamic footprints, research on the comparisons between the contact area of static and dynamic footprints in the forensic context are limited. The present study compares the contact area of static and dynamic bare footprints to determine if statistically significant differences exist between the two. Static and dynamic footprints were obtained from a sample of randomly-selected 461 Jatt Sikh adults (230 males and 231 females) of Indian origin between the ages of 19 and 32 years. The footprint contact area was calculated from each footprint (excluding the toes) using a PedoGRID® sheet. No statistically significant differences were observed between the contact area of static and dynamic footprints for each foot among males and females. However, statistically significant differences between both the sexes were found in the footprint contact areas of both footprint types. The right dynamic footprint contact area was found to be the most predictive measurement for classifying and estimating sex from a footprint’s contact area. The study has implications in the analysis of footprints recovered from crime scenes.     

The Development of a Reduced-Item Structured Inventory of Malingered Symptomatology (SIMS)

Effort assessment is a relevant area in neuropsychological assessment. There are well-established self-report measures, such as the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) FBS Symptom Validity Scale (FBS; Lees-Haley, English & Glenn, Psychological Reports 68: 203-210, 1991) and MMPI-2 Response Bias Scale (RBS; Gervais, Ben-Porath, Wygant & Green, Assessment 14: 196, 2007). However, there is also a need for brief measures of symptom exaggeration. The Structured Inventory of Malingered Symptomatology (SIMS) appears to be a promising self-report measure of symptom validity (e.g., Smith & Burger, Academy of Psychiatry and the Law 25: 183-189, 1997). In order to understand the psychometric properties of the SIMS, a comprehensive item analysis was performed with the questionnaire. Items were removed due to invariable response or lack of relationship with the total SIMS. Receiver operating characteristics (ROC) curve analyses were completed using RBS and FBS Symptom Validity Scale (FBS) of the MMPI-2 with items grouping from the SIMS indices. The results found that limiting the number of items did not affect overall utility. The abbreviated indices on the SIMS had excellent discrimination with the neurologic impairment (NI) and affective disorder (AF) scales and good discrimination with psychosis (P) and amnesic disorder (AM) scales of the SIMS. The briefer measure allows for less time required to administer the measure, while still maintaining the integrity of the SIMS.     

Reliability of a two-dimensional footprint measurement approach

Although footprint evidence can be taken from the scene of a crime, the science underpinning such measurement in forensic science has not been fully explored.A literature search revealed various measuring approaches, all of which demonstrated either little or no measurement rigour in terms of reliability. The aim of this study was to apply a robust measurement approach for testing the reliability of two-dimensional footprint impressions.Three dynamic and three static footprints were taken from the right foot of thirty female and thirty one male volunteers using the ‘Inkless Shoeprint Kit’. The images were digitised. Lengths, widths and angles were measured using a selection of currently employed methods.An investigation of the reliability of the chosen measuring method suggested high intra-rater agreement: for example, the length measurement suggested an intraclass correlation coefficient (ICC) 0.99, 95% Confidence Interval (CI) ? 0.28 to 0.01, standard error of measurement (SEM) 0.07, Limits of Agreement (LOA) ? 0.91 to 0.65.Inter-rater reliability between three operators was also high: SEM ranged from 0.05 mm to 0.07 mm, ICC 0.99.Our study has established a reliable two-dimensional measuring technique that could be used for footprint comparison in further research.     

Perceptions of blind proficiency testing among latent print examiners

In recent years, scholars have levied multiple criticisms against traditional proficiency testing procedures in forensic laboratories. Consequently, on several occasions, authorities have formally recommended that laboratories implement blind proficiency testing procedures. Implementation has been slow, but laboratory management has increasingly expressed interest in initiating blind testing in at least some forensic disciplines, with some laboratories conducting blind testing in almost all disciplines. However, little is known about how a key population perceives blind proficiency testing, i.e., forensic examiners. We surveyed active latent print examiners (N = 338) to explore perceptions of blind proficiency testing and determine whether beliefs varied between examiners who work for laboratories with and without blind proficiency testing. Results suggest that examiners do not hold particularly strong beliefs about such procedures, but that examiners who work in laboratories with blind proficiency testing procedures view them significantly more positively than those who do not. Further, examiner responses provide insight into potential obstacles to continued implementation.     

Stature and Body Weight Estimation from Various Footprint Measurements Among Egyptian Population

Abstract: Analysis of footprints can reveal very important clues which can be used as a forensic evidence and help in the estimation of stature and body weight of an individual. In this work, bilateral footprints were obtained from 50 male Egyptian medical students ranging in age between 18 and 25. Nine measurements were taken on each footprint. The result revealed significant bilateral asymmetry (p < 0.001) except foot breadth at ball. The significant and positive highest correlation coefficients with stature were shown by toe‐5 length on right side (R = 0.58) and with body weight by foot breadth at ball on left side (R = ?0.52). Regression equations presented smaller standard errors of estimate (3.52–4.69) in determination of stature than those in estimation of body weight (4.05–5.28). In conclusion, this study has provided equations that help to estimate stature and body weight from footprint measurements among Egyptians.     

Nondestructive Differentiation of Polyester Single White Fibers Using Synchrotron Radiation Microbeam X-ray Fluorescence Spectrometry with Vertical Focusing

In this study, the nondestructive differentiation of individual white polyester clothing fibers was accomplished via synchrotron radiation microbeam X-ray fluorescence (SR-μ-XRF) analysis. SR-μ-XRF with vertical focusing is a useful nondestructive method for the analysis of a single polyester clothing fiber. Kirkpatrick–Baez (KB) mirror was used to vertically focus 20 keV X-rays for the analysis of 22 individual white polyester fibers taken from clothing commonly sold in Japan. SR-μ-XRF with a vertical focused 2 μm (V) × 300 μm (H) beam was approximately 12.8 times more sensitive than SR-XRF with an unfocused 300 μm (V) × 300 μm (H) beam for the detection of elements in single fibers. The minimum detection limits (MDLs) of the SR-μ-XRF method were 8.15 ppm for Cl and 0.06 ppm for Br. In addition to Ti in TiO₂ delustering agents, Zr and Nb impurities in the delustering agents were detected in individual fibers. Sb from a polymerization catalyst and Co from a transesterification catalyst were also detected in individual fibers. Comparing the Ti K_β/Sb L_α,β and Zr K_α/Nb K_α X-ray intensity ratios was a useful way to distinguish individual clothing fibers, and 98% of the fibers were differentiated when additional trace elements were used as discrimination indicators.     

Meeting a Forensic Podiatry Admissibility Challenge: A Daubert Case Study

This article is an introduction to the United States Supreme Court's standard of admissibility of forensic evidence and testimony at trial, known as the Daubert standard, with emphasis on how this standard applies to the field of forensic podiatry. The author, a forensic podiatrist, provided law enforcement with evidence tying a bloody sock‐clad footprint found at the scene of a homicide to the suspect. In 2014, the author testified at a pretrial hearing, known as “a Daubert hearing,” to address the admissibility of this evidence in court. This was the first instance of forensic podiatry being the primary subject of a Daubert hearing. The hearing resulted in the court ordering this evidence admissible. The expert's testimony contributed to the suspect's conviction. This article serves as a reference for forensic podiatrists and experts in similar fields that involve impression evidence, providing evidentiary standards and their impact on expert evidence and testimony.     

The Dynamic Prediction of Criminal Recidivism: A Three-wave Prospective Study

A three-wave, prospective panel design was used to assess the extent to which static and dynamic risk factors could predict criminal recidivism in a sample of 136 adult male offenders released from Canadian federal prisons. Static measures were assessed only once, prior to release while dynamic measures were assessed on three separate occasions: pre-release, 1 month, and 3 months post-release. Recidivism was coded during an average of 10.2-month follow-up period (SD = 19.2). A series of Cox regression survival analyses with time-dependent covariates and Receiver Operator Characteristic (ROC) analyses were conducted to assess predictive validity. Although the combined static and time-dependent dynamic model (AUC = .89, CI = .81–.93) significantly (p < .01) outperformed the pure static model (AUC = .81, CI = .73–.87) the confidence intervals did overlap to some extent. Implications for dynamic risk assessment and management are discussed.

Age estimation by pulp/tooth area ratio in canines: Cameriere's method assessed in an Indian sample using radiovisiography

Age estimation of an individual whether living or dead is an intimidating task in forensic investigations. Since teeth are more resistant to most peri- and post-mortem changes, they are frequently used for identification and age estimation when skeletal remains are in poor condition. However, most methods are destructive and warrant extraction of teeth which is not feasible in living individuals. Cameriere's et al. put forth a radiographic method of age estimation by pulp to tooth area ratio (AR) in canines and revealed a linear regression between age and the AR. In the present study, we estimated the AR in 456 canines (upper, lower and both) in an Indian sample (114 males and 114 females) using radiovisiography technique. Linear regression equations were derived for upper canine, lower canine and both using the AR to estimate chronological age. Additionally, the efficacy of these equations was also evaluated in younger age group (<45 years). The formulas derived, i.e., age = 96.795 ? 513.561x₁ (Eq. (1)) for upper canine, age = 88.308 ? 458.137x₂ (Eq. (2)) for lower canine and age = 99.190 ? 283.537x₁ ? 306.902x₂ + 400.873x₁x₂ (Eq. (3)) for both the canines were applied to predict the chronological age. The mean value of residuals using these regression equations ranged from 4.28 to 6.39 years with upper canine equation generally giving a precise result. When these equations were applied for younger ages (<45 years), the regression equation derived from both canines gave a better result (mean residual 2.70 years). Overall these equations were better able to predict the age in younger ages, i.e., up to 45 years.     

Monitoring of Levamisole Concentration in Serum of Traffic Participants after Cocaine Consumption

This study highlights the problem of levamisole‐adulterated cocaine in context of active traffic participation. For the purposes of levamisole concentration monitoring in human serum, an analytical method based on LC‐MS/MS and solid‐phase extraction was applied. A Luna 5 μm C18 (2) 100 A, 150 mm × 2 mm column and a mobile phase consisting of A (H₂O/methanol = 95/5, v/v) and B (H₂O/methanol = 3/97, v/v), both with 10 mM ammonium acetate and with 0.1% acetic acid (pH = 3.2), were used. The validation experiments demonstrated that the method applied was appropriate for levamisole quantification in human serum. For 23% of levamisole‐positive samples, the concentrations exceeded 20 ng/mL. Therefore, the interaction of this drug with cocaine has to be considered as important for active traffic participation. As a consequence, monitoring of levamisole concentration in human serum is recommended, as long as it is used as cocaine adulterant.     

Characteristics of electrically injured skin from human hand tissue samples using Fourier transform infrared microspectroscopy

This technical note describes a method for distinguishing normal skin tissue samples from those electrically injured by Fourier transform infrared microspectroscopy (FTIR MSP). Furthermore, the infrared spectral features of electrically injured cells and tissues were evaluated to identify molecular changes in epidermal cells. In the present study, 20 human hand tissue samples were evaluated macroscopically and histopathologically. The electrically injured skin samples were subdivided into 2 regions [normal cell regions (NCRs) and polarized cell regions (PCRs)] and 14 major spectral absorption bands were selected. The spectral results showed that the band absorbance at 1080, 1126, 1172, 1242, 1307, 1403, 1456, 1541, 2852, 2925, 2957, 3075, and 3300 cm^− 1 increased significantly both in the stratum and non-stratum corneum of the PCRs in electrically injured skin tissues samples. No significant difference was found between normal skin and the NCR of the electrically injured skin samples. The band absorbance ratios of A₁₁₇₂/A₁₁₂₆, A₁₄₅₆/A₁₄₀₃, and A₂₉₂₅/A₂₉₅₇ were significantly increased, whereas the A₁₆₅₂/A₁₅₄₁ ratio was decreased in the PCR of the stratum corneum and non-stratum corneum. Baseline changes from 4000 to near 1737 cm^− 1 were observed in the spectra of the electrically injured skin samples, which were interpreted in terms of the pathological process involved in electrical injury. FTIR-MSP presents a useful method to provide objective spectral markers for the assisted diagnosis of electrical marks.     

Experimental long-distance haplotyping of OCA2-HERC2 variants

The regulatory HERC2 SNP, rs12913832, is strongly associated with blue and brown eye colour. However, eye colour in heterozygous rs12913832 individuals is observed to vary greatly. Missense mutations in OCA2, such as rs1800407 and rs74653330, are associated with lighter eye colour in some but not all heterozygous rs12913832 individuals. Determining the physical linkage of these variants might help to further explain eye colour variation. So far, experimental haplotyping of these variants has been challenging because the genomic distance between them (∼ 135 kb) exceeds the fragment lengths produced by commonly used DNA isolation kits. The aim for this study was to explore novel methods for long distance haplotyping to assess associations between OCA2-HERC2 haplotypes and eye colour. DNA was isolated from frozen blood samples collected from Norwegians that are known to be heterozygous for both HERC2 rs12913832 and OCA2 SNPs, either rs1800407 (n = 23) or rs74653330 (n = 17), using the newly commercially available Monarch® HMW (heigh molecular weight) DNA Extraction Kit (New England BioLabs_inc). We successfully isolated DNA fragments up to 210 kb, which were long enough to haplotype OCA2-HERC2 loci by droplet digital PCR (ddPCR). Three haplotypes were observed in the study population: rs12913832:A-rs1800407:T in 22/23 individuals, rs12913832:A-rs1800407:C in 1/23 individuals and rs12913832:A-rs74653330:T in 16/16 individuals. As expected, all individuals with the rs12913832:A-rs74653330:T haplotype had intermediate to blue eye colour. However, the rs12913832:A-rs1800407:T haplotype was observed in both blue and brown-eyed individuals, suggesting more research is needed.     

The Portuguese adaptation of the Gudjonsson Suggestibility Scale (GSS1) in a sample of inmates

This paper comprises two studies which address the validity of the Portuguese adaptation of the Gudjonsson Suggestibility Scale, GSS1. In study 1, the means and standard deviations for the suggestibility results of a sample of Portuguese inmates (N = 40, M_age = 37.5 years, SD = 8.1) were compared to those of a sample of Icelandic inmates (Gudjonsson, 1997; Gudjonsson & Sigurdsson, 1996). Portuguese inmates' results were in line with the original results. In study 2, the means and standard deviations for the suggestibility results of the sample of Portuguese inmates were compared to those of a general Portuguese population sample (N = 57, M_age = 36.1 years, SD = 12.7). The forensic sample obtained significantly higher scores in suggestibility measures than the general population sample. ANOVA confirmed that the increased suggestibility in the inmates sample was due to the limited memory capacity of this latter group. Given that the results of both studies 1 and 2 are in keeping with the author's original results (Gudjonsson, 1997), this may be regarded as a confirmation of the validity of the Portuguese GSS1.     

On the consequences of ignoring genetic influences in criminological research

Purpose

Many criminological scholars explore the social causes of crime while giving little consideration to the possibility that genetic factors underlie the observed associations. Indeed, the standard social science method (SSSM) assumes genetic influences do not confound the association between X and Y. Yet, a nascent stream of evidence has questioned the validity of this approach by revealing many criminological variables are at least partially affected by genetic influences. As a result, a substantial proportion of the literature may be misspecified due to uncontrolled genetic factors. No effort has been made to directly estimate the extent to which genetic confounding has biased the associations presented in criminological studies.

Methods

The present study seeks to address this issue by drawing on simulated datasets.

Results/Conclusions

Results suggest genetic confounding may account for a negligible portion of the relationship between X and Y when their correlation (r_yx) is larger than the correlation between genetic factors and Y (i.e., r_yx > r_yg). Genetic confounding appears to be much more problematic when the correlation between X and Y is in the moderate-to-small range (e.g., r_yx = .20) and the genetic effect is in the moderate-to-large range (e.g., r_yg ≥ .30).     

Computer assisted modeling of ethyl sulfate pharmacokinetics

For 12 volunteers of a drinking experiment the concentration–time-courses of ethyl sulfate (EtS) and ethanol were simulated and fitted to the experimental data. The concentration–time-courses were described with the same mathematical model as previously used for ethyl glucuronide (EtG). The kinetic model based on the following assumptions and simplifications: a velocity constant k_form for the first order formation of ethyl sulfate from ethanol and an exponential elimination constant k_el. The mean values (and standard deviations) obtained for k_form and k_el were 0.00052 h^?1 (0.00014) and 0.561 h^?1 (0.131), respectively. Using the ranges of these parameters it is possible to calculate minimum and maximum serum concentrations of EtS based on stated ethanol doses and drinking times. The comparison of calculated and measured concentrations can prove the plausibility of alleged ethanol consumption and add evidence to the retrospective calculation of ethanol concentrations based on EtG concentrations.