利用立体赤足迹后跟后缘裂纹特征破获一起重大盗窃案

1983年,我区某县发生一起重大盗窃案,现场勘查中仅提取到一枚残缺不全的立体赤足迹。经检验,足迹为后跟部分,反映出的后跟大小、形态、落脚点、重压面的形态位置等特征均与嫌疑人赤足足迹样本后跟部位反映的特征相同,但缺少特定、稳定的特征,后我们利用两者后跟后缘所反映出的裂纹痕迹形态和位置的关系,认定了作案分子,破获了此案。     

对足迹检验鉴定理论的思考

我国的足迹检验技术在80年代和90年代得到了较大的发展,足迹检验技术从步法检验、形象检验,发展到鞋底磨损检验、足迹动力形态检验、足迹定量化检验等。特别是近几年,足迹检验中各学派、各门类的各种检验技术内容丰富,方法多样,正在逐步形成具有中国特色的足迹学体系,在侦查破案中发挥了重要作用。目前,常用的足迹鉴定包括:1赤足足迹的鉴定主要以足迹的大小、形象、轮廓、重压部位的密度、乳突花纹、残缺部位、是否变形等特征为赤足足迹进行同一认定,赤足足迹的鉴定又分为平面赤足足迹的鉴定和立体赤足足迹的鉴定。2鞋印足迹的形象鉴定主要…     

浅议足迹检验中影响特征形成的几种因素

本文所述几点,是对足迹检验中影响特征形成的几种因素的简单归结,与大家共同探讨(以平面赤足迹反映的特征为准).1 坡度对足迹的影响1.1 上坡时坡度与重压部位面积、位置的关系上坡时足迹特征反映为整个脚部重压后移,在正常足迹中反映不出的三、四趾压加重,掌部重压主要反映在第一跖区.且坡度越大,第一跖重压反压越明显.跟压加重,落脚部位不明显.在一些坡面比较平滑的客体上,这时鞋印的前边缘常常后移,使     

利用不同鞋种鞋印长度推断身高差值探究

目的研究不同鞋种的鞋印长度与赤足平面足迹长度的差值数据,为利用现场各类不同穿鞋足迹分析身高等人身特点提供科学依据,也为足迹定量化分析与检验奠定基础。方法针对犯罪现场中常见鞋种,选取不同的鞋号,采集对不同足长、身高的实验者正常行走所捺印的穿鞋样本与赤足样本,对穿鞋足迹鞋印长度与赤足足迹长度进行统计与计算。结果得出不同鞋种鞋印长度与赤足平面足迹长度的差值数据。结论应用现场穿鞋足迹分析身高等人身特点时,应针对不同的鞋种,减去相关系数,结合原有身高分析公式,综合分析身高。     

赤足跖后缘自动提取与自适应变模型特征识别

将经典Snake模型与自适应变模型相结合的算法，快速提取图像中的开边缘并识别边缘形状，实现赤足足迹跖后缘的自动提取与形状识别。首先，对原图像校正、平滑去噪，由数学形态学方法得到Snake模型的初始轮廓，迭代求解实现跖后缘的快速、精确提取。然后，由高次多项式进行数字滤波，再对滤波后的边缘曲线，利用先验知识，依据平均曲率的变化，自适应地选取不同的函数模型，提取出相应特征，自动识别边缘形状。该方法边缘提取准确，特征提取合理，使计算机总体识别率达到90％。     

平面赤脚印形状特征量化技术初探

赤足形状参量的提取是利用赤足迹进行个体识别技术研究的关键技术,传统的手工测量和手工描绘都会产生较大的误差,本文利用图像处理技术从足迹图中提取赤足形状的轮廓线,然后利用AutoCad软件测量特征点的参数,建立了利用计算机自动提取赤足形状参数的方法。     

“黄金分割律”在足迹检验中的应用

引用黄金分割律的有关理论与方法,讨论其在足迹检验、特别是残缺足迹检验方面应用的可行性及现实性,具体介绍了足迹各部位特征点与黄金分割律的相关关系,从而达到根据残缺足迹分析完整足迹特征的目的.     

残缺鞋印留痕部位的确定

在犯罪现场上，经常遇到犯罪分子遗留的残缺鞋印。这里所说的“残缺鞋印”是指那些没有反映出鞋底形态全貌的鞋印。例如只反映出鞋底的前掌中部或只反映出鞋底后跟某一部分的鞋印等等。这类足迹可利用的特征少，给检验鉴定工作带来一定的困难。要分析利用此类足迹，确定特征位置，提高检验效率，首先要确定其留痕部位。做好这项工作对提高现场足迹的利用率非常重要。笔者从鞋底的花纹分布规律、伴生痕迹以及鞋底的磨损特征等方面阐述如何分析确定残缺鞋印的留痕部位。１根据残缺鞋印反映的周边形状及鞋底花纹、图案分析确定由鞋底花纹分布规…     

残缺立体足迹的拍照方法

在现场勘查实践中,经常遇到面积小、立体感不强的残缺立体足迹.对这类足迹的拍照,如采用标准镜头加接圈的方法,则因拍照距离太短,影响拍照效果;如不加接圈直接拍照,则因成像太小,残缺立体足迹的细微特征无法显示,因而成为刑事照相中的一个难题.通过实践发现,采用中长焦镜头加接圈,再辅以适当的配光进行拍照,则较好地解决了对残缺立体足迹进行拍照这一难题.     

谈根据足迹分析行为人的人身特点

足迹是犯罪现场上遗留率最高的一类痕迹,是侦查破案和刑事诉讼中最为常见的重要物证之一。足迹检验技术是同刑事犯罪作斗争的重要手段之一,通过对现场足迹的分析,可以为侦查破案提供线索。本文总结了男女性别各自的足迹一般反映特征,分析了各年龄阶段所反映出来的步幅特征、步法特征和各种体态的人足迹特征的反映,并介绍了几种根据足迹推算年龄、身高的方法。以期能为足迹检验工作提供更加科学的方法和更准确的数据。     

Estimation of stature from footprint and foot outline dimensions in Gujjars of North India

Estimation of individual's stature is an important parameter in forensic examinations. Examination of footprints provides important evidence in a crime scene investigation and helps in estimation of stature of a criminal. Analysis of bare footprints is often carried out in developing countries like India where the footprints are frequently recovered at the scene of crime. The present study attempts to reconstruct stature in a sample of 2080 bilateral footprints and foot outlines collected from 1040 adult male Gujjars of North India ranging in age from 18 to 30 years. Bilateral footprints and foot outlines of each individual were measured for ten and eight measurements, respectively. The results indicate that T-2 length (length of the footprint from heel to 2nd toe) and T-5 length in footprint and T-1 length, T-4 length and breadth at ball in foot outline show statistically significant bilateral asymmetry. Significant and positive correlation coefficients exist between stature and various measurements of footprint and foot outline (P<0.001 and 0.01) except toe 1-5 angle of declination which shows insignificant correlation coefficient. The highest correlation coefficients were shown by the toe length measurements (0.82-0.87) indicating a close relationship between the stature and these measurements. Regression analysis presents smaller mean errors (2.12-3.92cm) in estimation of stature than those of division factor method (3.29-4.66cm), thus, gives better reliability of estimate than the latter. The regression equations were also checked for their accuracy by comparing the actual stature with estimated stature.     

Reliability of a two-dimensional sock-clad footprint linear measurement method

A two-dimensional linear measurement approach for footprints, herein referred to as the “Reel Method,” has been shown to be valid and reliable when used on bare footprints, however, few measurement approaches have been examined on sock-clad footprints. The present investigation examines the validity and reliability of the Reel Method as a two-dimensional linear measurement approach for use on sock-clad footprints.A walking, mid-gait footprint was collected from 30 volunteer participants using the Identicator Inkless Shoe Print Model LE 25P system. The width of the ball of the foot, calcaneal width, and distance from the most posterior aspect of the heel to the most distal aspect of the first toe were each measured and compared between and within three raters. The statistical analysis demonstrated high reliability of the Reel Method among these three raters. The data were found to be normally distributed, and measurements were consistent between and within raters. 95% Intraclass Correlation coefficients, 95% Bland-Altman Limits of Agreement and 95% Standard Error of Measurement determined high statistical agreement between and within raters, demonstrating that the Reel Method is reliable and thus valid for the linear measurement of sock-clad footprints.     

Establishing correlation of footprints with body weight--forensic aspects

Analysis of footprints can reveal very important clues which can be used as forensic evidence in crime scene investigation. Apart from giving idea about the bare foot morphology and individualistic characteristics, the footprints are also indicative of the body size of the person. The present study is an attempt to establish the correlation between footprints and body weight of individuals. The sample for the present study consists of 50 male subjects ranging in age from 18 to 30 years. The subjects belonging to Gujjar caste were randomly taken from a village near Chandigarh city in North India. Three kinds of bilateral footprints were taken from each subject. First, the footprints with the subject's normal weight were taken, the footprints were taken when the subject holds 5 kg weight in his hands, then the footprints were taken when the subject holds 20 kg weight in his hands. In this way, the present study analyses 300 bilateral footprints obtained from 50 individuals. Nine measurements were taken on each footprint using precise and defined landmarks. The measurements of these three kinds of footprints were compared with each other and t-test was employed to see the significant variation. Some of the measurements of the footprints were altered significantly when the subject was subjected to 20 kg weight. However, there is no significant change when the subject holds 5 kg weight in his hands. Body weight was also estimated using regression method from the measurements of these three kinds of footprints. The utility of the study in offences like sexual assault, homicide, theft, burglary, mugging, stealing, shoplifting, dacoity, etc. has been discussed.     

Two-dimensional metric comparison between dynamic bare and sock-clad footprints for its forensic implications – A pilot study

Footprints may be present at crime scenes as physical evidence. This pilot study compares two-dimensional measurements of bare and sock-clad footprints to determine if significant differences or similarities exist. Dynamic footprints were collected from 30 males and 20 females between the ages of 20 and 61?years old (mean of 28.2?years) using the Identicator Inkless Shoe Print Model LE 25P system. A midgait protocol was employed for obtaining footprints. The fifth and sixth footprint of gait were collected for the right and left foot, respectively, in both sock-clad and barefoot trials. The footprint measurements between sock-clad and bare footprints were compared. The results did not indicate any significant difference (p?>?.05) between bare and sock-clad foot length measurements for right or left feet. Significant differences were seen for the width measurements between bare and sock-clad footprints. These findings have forensic implications, particularly in criminal cases where it is unclear if a footprint impression is from a sock-clad foot or a bare foot. This study shows that such a determination is generally not necessary when utilizing two-dimensional measurements for length comparison between a bare and sock-clad footprint. However, if width measurements are being evaluated, the distinction between bare and sock-clad footprints should be considered.     

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.     

现场残缺鞋印的分析与利用

在刑事案件现场残缺鞋印出现率较高,可是多种因素导致残缺鞋印的提取率和鉴定率却越来越低,使得残缺鞋印在案件侦破或诉讼过程中未发挥其应有的作用。事实上,残缺鞋印反映出的信息可以分析鞋种、刻画嫌疑人特征、识别鞋只等检验鉴定工作,根据现场残缺鞋印的形成机制,从主观和客观两方面分析了现场残缺鞋印提取和鉴定率低的原因,通过实际案例说明其在案件侦破及诉讼中发挥的特殊作用,并列举了残缺鞋印提取和检验时应注意一些问题．为现场勘验人员和检验人员提供参考。     

Ghosting phenomenon in static and dynamic footprints in India and the United States

Ghosting is the phenomenon that exists when a footprint has a lighter area around the tip of one or more toes or a shadow-like area at the back of the heel. To date, ghosting has been considered primarily a finding of dynamic (walking) footprints, rather than static (standing) footprints. The prevalence of ghosting in static footprints is unknown, and research on its presence in static and dynamic footprints from the same participant is sparse, as are studies on its occurrence in different geographic populations. This study is among the first to evaluate the occurrence of ghosting in the static and dynamic footprints from a particular individual with participants in two geographic populations.A combination of both inkless and ink footprint collection systems were used to obtain a total of 206 bare footprints from 103 adult participants from the United States and India. The data comprised 103 static and 103 dynamic footprints.Ghosting occurred significantly in static footprints, though less frequently than in dynamic footprints. Ghosting in static footprints was seen most often at the first toe, followed by the third and second respectively. This aspect appeared least at the heel. In dynamic footprints, it occurred most at the first toe, followed by the second and fourth toes, and then the third toe and the heel. The prevalence of ghosting in footprints from the United States and India differed in their locations, notably at the first and second toes in the static footprints and at the heel in the dynamic footprints.     

Age-related factors in the relationship between foot measurements and living stature and body weight

The measurements of feet and footprints are especially important in forensic identification, as they have been used to predict the body height and weight of victims or suspects. It can be observed that the subjects of forensic-oriented studies are generally young adults. That is to say, researchers rarely take into consideration the body's proportional changes with age. Hence, the aim of this study is to generate equations which take age and sex into consideration, when stature and body weight are estimated from foot and footprints dimensions. With this aim in mind, we measured the stature, body weight, foot length and breadth, heel breadth, footprint length and breadth, and footprint heel breadth of 516 volunteers (253 males and 263 females) aged between 17.6 and 82.9 years using standard measurement techniques. The sample population was divided randomly into two groups. Group 1, the study group, consisted of 80% of the sample (n = 406); the remaining 20% were assigned to the cross-validation group or Group 2 (n = 110). In the first stage of the study, we produced equations for estimating stature and weight using a stepwise regression technique. Then, their reliability was tested on Group 2 members. Statistical analyses showed that the ratios of foot dimensions to stature and body weight change considerably with age and sex. Consequently, the regression equations which include these variables yielded more reliable results. Our results indicated that age and sex should be taken into consideration when predicting human body height and weight for forensic purposes.     

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.     

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.