The value of DNA material recovered from crime scenes

Abstract:  DNA material is now collected routinely from crime scenes for a wide range of offenses and its timely processing is acknowledged as a key element to its success in solving crime. An analysis of the processing of approximately 1500 samples of DNA material recovered from the property crime offenses of residential burglary, commercial burglary, and theft of motor vehicle in Northamptonshire, U.K. during 2006 identified saliva and cigarette ends as the main sources of DNA recovered (approximately 63% of samples) with blood, cellular DNA, and chewing gum accounting for the remainder. The conversion of these DNA samples into DNA profiles and then into matches with offender profiles held on the U.K. National DNA database is considered in terms of the ease with which Crime Scene Examiners can recover DNA rich samples of different sources, the location of the DNA at the crime scene, and its mobility. A logistical regression of the DNA material recovered has revealed a number of predictors, other than timeliness, that greatly influence its conversion into a DNA profile. The most significant predictor was found to be Crime Scene Examiner accreditation with offense type and DNA sample condition also being relevant. A similar logistical regression of DNA samples profiled that produced a match with an offender on the U.K. National DNA database showed no significance with any of the predictors considered.     

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。     

Estimation of stature from hand impression: a nonconventional approach

Stature is used for constructing a biological profile that assists with the identification of an individual. So far, little attention has been paid to the fact that stature can be estimated from hand impressions left at scene of crime. The present study based on practical observations adopted a new methodology of measuring hand length from the depressed area between hypothenar and thenar region on the proximal surface of the palm. Stature and bilateral hand impressions were obtained from 503 men of central India. Seventeen dimensions of hand were measured on the impression. Linear regression equations derived showed hand length followed by palm length are best estimates of stature. Testing the practical utility of the suggested method on latent prints of 137 subjects, a statistically insignificant result was obtained when known and estimated stature derived from latent prints was compared. The suggested approach points to a strong possibility of its usage in crime scene investigation, albeit the fact that validation studies in real-life scenarios are performed.     

An investigation into the differentiating characteristics between car key burglars and regular burglars

Car key burglary has recently become the focus of empirical investigation as offenders, no longer able to steal vehicles without first obtaining their keys, resort to "burgling" target properties. Research surrounding the modus operandi of these offenses is beginning to emerge; however, little attention has been paid to investigating the characteristics of car key burglary offenders. Challenging the assumption that car key burglary offenses are perpetrated by regular burglars, this study aims to differentiate between offenders. Logistic regression analysis of 110 car key and 110 regular burglary offenders revealed that car key burglars are more likely to have previous vehicle theft convictions and are also more likely to be detected on information supplied to the police than regular burglars. Regular burglars are more likely to have previous shoplifting convictions. It was concluded that car key burglars are a distinct sample of offenders and the implications of these findings are discussed.     

The influence of footwear sole hardness on slip initiation in young adults

Slips occur when the friction demand of an individual exceeds the friction available from the shoe/floor interface. Shoe sole hardness is one of the factors thought to influence friction demand and available friction. The purpose of this study was to determine the influence of footwear sole hardness on the probability of slip initiation. Forty young adults were randomized into a hard or soft sole group. Slip events during the slippery floor trials were documented using a motion analysis system. The proportion of slip events in the hard sole group was greater than that in the soft sole group. The difference between utilized and available friction accurately predicted 90% of slip outcomes. Our data support the premise that individuals wearing shoes with harder soles are at greater risk for slipping. The results of this study suggest that shoe sole hardness should be considered when designing footwear aimed at decreasing slip risk.     

论公安机关鉴定体制改革的方向———以犯罪现场勘查与刑事技术鉴定的区别为视角

犯罪现场勘查与刑事技术鉴定工作是案件侦查的起点和基础,在刑事侦查工作中扮演着重要的角色,然而从我国实际情况来看,＂自勘自鉴＂、＂自侦自鉴＂、＂勘鉴不分＂的现象非常普遍,这一点与我国《刑事诉讼法》的立法精神相违背,有碍司法公正和侦查工作的顺利进行。为此,必须厘清犯罪现场勘查与刑事技术鉴定的区别,健全犯罪现场勘查与刑事技术鉴定的工作体制,实行＂侦勘合一＂的工作机制,使公安机关的鉴定机构与侦查部门分离成为公安机关鉴定制度改革的方向。