动脉喷溅血迹动力学及形态学的模拟实验观察

目的观察不同压力、管径对在水平方向上形成的喷溅状血迹的喷射距离及形态的影响。方法建立室内现场环境,利用自制的模拟喷射装置,在60～210mmHg范围内设6种压力,在1.5～4.5mm范围内设4种管径条件,于50、100、150cm 3种高度,制作动脉喷溅血迹。观察水平面上不同喷射高度的喷溅血迹的分布范围、血迹大小及形态特征,并测量其距离,采用SPSS 13.0统计软件进分析,并进行方差检验。结果在不同高度,血液喷射距离随压力增大而增加,随管径增大而减小,两因素间存在交互作用,距离与压力及管径存在较好的线性关系,可得出回归方程。而喷溅血迹的形态特征总体趋势为:高度越高圆形血滴直径约大;管径越粗,边缘毛刺状突起越明显;压力越大,喷射距离越远,且卫星状血迹逐渐增多,拖尾更拉长;随管径的增加,出现椭圆形血滴所需的压力越高。结论动脉喷溅血迹的形态及喷射距离的观察与测量,可用于推断命案现场喷溅源位置及人体受损伤时的体位。     

凶杀案现场血迹分析1例

1案例资料 1．1简要案情 某女,53岁,某日19时被发现死于出租房内。据调查,13时许曾有人见过死者,15时许死者家门关闭,邻居未能与其联系上,晚饭后房东用备用钥匙开门后发现人已死亡,遂报警。     

血迹分析在现场血迹提取中的应用

对命案现场血迹的研究和分析历来是命案现场勘验及现场分析的重要组成部分。传统上,对现场血迹的研究分析侧重于对血迹形态及其形成过程的分析和研究,通过对现场血迹的分布规律及形态特征的观察和测量,判断血迹来源与形成机制,进而推断血迹与案件或犯罪事实之间的关系和过程[1]。     

现场血迹分析1例

<正>1 案例资料 案情简介 某日凌晨2时许，某路边一汽修厂的值班员听到打斗声，出来观望，发现路上有一男子推1辆摩托车，另一男子趴在地上，手抓摩托车尾架，旁边一女子正用刀砍抓摩托车尾架的手，即报警。民警到达现场发现一男子满身是血，死在路上，在尸体前方     

血迹形态在命案现场中的应用1例

血迹是凶杀案件中最常见的痕迹物证之一。根据血迹的种类、数量、分布、形态、色泽、检验鉴定和形成方式等综合分析，可以对出血来源，出血部位，受伤时体位，受伤后的活动过程、案件性质、作案地点、作案时间、作案工具、作案人数和作案过程等做出推断，为侦察破案提供依据和证据支持。笔者通过详细的现场勘验，依据现场遗留血迹，分析血迹的形成方式和过程，来解读血迹中包含的犯罪信息。     

二次溅落状血迹形态的模拟实验观察

目的观察二次溅落状血迹的形态特征,探讨其形成机理及与行为方式的关系。方法建立室内现场环境,用10mL血液,以单滴连续滴落或一次性倾倒方式,从10～160 cm高度以10 cm为间隔,制作二次溅落状血迹模型;用棍棒打击及撞击方式制作低位打击及头部撞击溅落血迹模型。观察各种血迹分布,并分析比较其形态差异。结果二次溅落状血迹和头部撞击溅落状血迹在垂直面上均形成倒三角形空白区域的分布形态,但前者分布面积较后者小;低位打击溅落在垂直面上的血迹无此特征,且打击飞溅血滴的飞行角度大于二次溅落血迹。结论利用二次溅落状血迹的形态特征,对于鉴别低位溅血、分析行为方式、证实相关证词具有重要价值。     

圆形滴状血迹形态与血滴体积、撞击速度的相关性

目的观察不同体积的血滴以3种撞击速度垂直撞击3种不同介质形成的滴状血迹形态及大小,并探讨其相关性。方法将8种不同体积（14～115IxL）的抗凝猪m形成血滴,以3种不同的撞击速度（3．1～5．4m／s）分别垂直滴落于白纸、玻璃及釉面地砖上,观察形成血迹的形态特征,测量其直径,并采用SPSS13．0统计软件进行分析。结果在3种撞击速度条件下,在3种介质上形成的滴状血迹直径均随血滴体积的增加而增大,血迹直径与血滴体积存在较好的线性关系,可得出回归方程（回归模型R2〉0．85,P〈0．01）;介质表面越粗糙,血迹直径越小;仅在自纸上发现血迹边缘有突起形成,且其数目随血滴体积的增加而增多。撞击速度及血滴体积存在较好的多重线性关系,可得出多重回归方程（回归模型R2〉0．90,P〈0．01）。结论垂直撞击形成的血迹形态及大小与血滴体积、撞击速度具有显著的相关性,可望用于推测出血源位置、受伤体位及出血部位载体。     

利用现场血迹分析犯罪行为

1案件简介李某,男,某日傍晚出外洗澡回家后被人杀死。李家位于居民区中心部位,为一座北朝南二层楼院落（院落面积40斫）,东南角为大门,院南侧为一东西走向的小巷。死者位于院中东侧靠近大门处,头北脚南,呈仰卧位（为120医务人员翻转形成）,死者面部、衣服上浸润大量血迹,双脚鞋底未见沾有血迹。北屋门挂有门帘,进北屋门为客厅,客厅北侧及东侧为卧室,二楼为空房。     

行为分析在命案现场分析中的应用1例

正命案现场离不开行为分析技术。行为分析主要依赖于现场及尸检所反映出的行为痕迹,还原罪犯作案动作,透视其生理、心理特征。本文以1起较为复杂的命案现场分析为例,探讨如何应用行为分析技术。1案例资料1.1简要案情及现场勘查某年11月4日下午4时许,指挥中心接刘某某(女,17岁)报案称:其父(刘某,41岁)、母(杜某,40     

1例他杀现场血迹分布的分析

<正>1 案例资料 2003年10月11日，在某茶山废弃屋内发现1具男尸，中心现场为一水泥砖结构的平房内。尸体仰卧于厨房靠东墙的地面上，头南脚北，其肩背部地面有一61cm×68cm的血泊；客厅中南面有一层新鲜泥沙，     

100例卖淫女被杀案的法医学检验分析

目的 分析卖淫女被杀案件的规律特点,为此类案件检验侦查提供参考.方法 采用描述性研究方法,对2005至2010年的100例卖淫女被杀案件进行回顾性分析.结果 此类案件66.7%发生于21时至3时之间,88.0%发生于城市.4、7两月发案最多.85.0%的案件发生于室内.95.0%的死者年龄在16～40岁.38.1%的死...     

A blind trial evaluation of a crime scene methodology for deducing impact velocity and droplet size from circular bloodstains

In a previous study, mechanical engineering models were utilized to deduce impact velocity and droplet volume of circular bloodstains by measuring stain diameter and counting spines radiating from their outer edge. A blind trial study was subsequently undertaken to evaluate the accuracy of this technique, using an applied, crime scene methodology. Calculations from bloodstains produced on paper, drywall, and wood were used to derive surface-specific equations to predict 39 unknown mock crime scene bloodstains created over a range of impact velocities (2.2-5.7 m/sec) and droplet volumes (12-45 microL). Strong correlations were found between expected and observed results, with correlation coefficients ranging between 0.83 and 0.99. The 95% confidence limit associated with predictions of impact velocity and droplet volume was calculated for paper (0.28 m/sec, 1.7 microL), drywall (0.37 m/sec, 1.7 microL), and wood (0.65 m/sec, 5.2 microL).     

微量生物物证提取套装在现场微量血痕DNA检验中的应用

目的 探讨微量生物物证提取套装应用于提取现场微量血痕DNA的检验效果.方法 将静脉血制成地面血痕.分别应用微量生物物证提取套装法和普通法提取血痕.分别于恒温摇床放置2、24、48、72、96 h(每组50份)进行血痕DNA检验,对比各组检验结果.结果 恒温摇床上分别放置24、48、72、96 h后,微量生物物证提取套装...     

An evaluation of the underlying mechanisms of bloodstain pattern analysis error

An experiment was designed to explore the underlying mechanisms of blood disintegration and its subsequent effect on area of origin (AO) calculations. Blood spatter patterns were created through the controlled application of pressurized air (20-80 kPa) for 0.1 msec onto suspended blood droplets (2.7-3.2 mm diameter). The resulting disintegration process was captured using high-speed photography. Straight-line triangulation resulted in a 50% height overestimation, whereas using the lowest calculated height for each spatter pattern reduced this error to 8%. Incorporation of projectile motion resulted in a 28% height underestimation. The AO xy-coordinate was found to be very accurate with a maximum offset of only 4 mm, while AO size calculations were found to be two- to fivefold greater than expected. Subsequently, reverse triangulation analysis revealed the rotational offset for 26% of stains could not be attributed to measurement error, suggesting that some portion of error is inherent in the disintegration process.     

Alteration of the Death Scene After Self‐stabbing: A Case of Sharp Force Suicide Disguised by the Victim as a Homicide?

This paper reports a case of a 72‐year‐old woman who was found dead in her bedroom with a 4 cm vertical stab wound in the abdomen. A bloodstained knife was found in the top drawer of her bedside table. The clothes worn by the victim showed no damage. A bloodstained vest and a sweater with frontal incisions were found far from the victim, in the bathroom and in the bedroom respectively. Several bloodstains were found in every room of the apartment. The evidence found during the forensic examination and, in particular, the Bloodstain Pattern Analysis, led the investigators to determine the manner of death, being consistent with a suicide with a long‐lasting physical activity after self‐stabbing. This report describes an unusual case of “disguised suicide,” in which the victim tried to cover‐up the suicide by changing her clothes and concealing the weapon, in the last minutes of her life.     

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.