Assessment of Maceration Techniques Used to Remove Soft Tissue from Bone in Cut Mark Analysis

Maceration techniques employed in forensics must be effective without compromising the bone's integrity and morphology, and prevent destruction of evidence. Techniques must also be fast, safe, easily obtainable and inexpensive; not all techniques currently employed are appropriate for forensic use. To evaluate the most suitable approach, seven techniques including current and new methodologies were applied to fresh, fleshed porcine ribs exhibiting cut marks. A sample size of 30 specimens per technique was examined under scanning electron microscopy at the cut mark and the surrounding uncompromised regions; a scoring system of effectiveness was applied. The previously unpublished microwave method fared best for bone and cut mark preservation. Sodium hypochlorite destroyed cut marks, and was deemed unsuitable for forensic analysis. No single technique fulfilled all criteria; however, this study provides a benchmark for forensic anthropologists to select the most appropriate method for their situation, while maintaining the high standards required by forensic science.     

Criminal Recidivism After Forensic Psychiatric Treatment. A Multicenter Study on the Role of Pretreatment,Treatment-Related,and Follow-Up Variables

This study examined associations between criminal recidivism after discharge from forensic treatment and variables related to either the time before the current forensic treatment, or the current forensic treatment, or the follow-up after discharge. Participants were treated in 12 forensic clinics according to section 63 of the German penal code. A patient was classified as a criminal recidivist when the patient or the aftercare reported that the patient was delinquent at follow-up. Patients without criminal recidivism were patients for which both perspectives (patient and aftercare) reported no delinquency at follow-up. Mann–Whitney U-tests and Fisher's exact tests were performed. Data to classify patients were available for N = 249 patients. Fifteen patients (6%) were classified as criminal recidivists. The follow-up was M = 12.58 (SD = 1.84) months, and the criminal acts occurred M = 6.00 (SD = 5.55) months after discharge. Differences between patients with and without criminal recidivism were found in pretreatment (young age at first crime, early onset of mental disorder, previous forensic treatments), treatment-related (disorder due to psychoactive substance use, gradual release abuses, outbreaks, assaults against staff, criminal act during treatment, type of discharge, outcome ratings), as well as follow-up variables (no specified housing situation, not being abstinent from psychoactive substances, inpatient readmission, course of outpatient treatment, course of mental disorder) (all p < 0.05). To conclude, it is important to consider variables related to the time before the current treatment, treatment-related variables, and variables related to the follow-up to identify the patients at risk of criminal recidivism after discharge from forensic treatment.     

Determining the Effectiveness of Noncontact Three-Dimensional Surface Scanning for the Assessment of Open Injuries

Noncontact three-dimensional (3D) surface scanning methods are used within forensic medicine to record traumas and other related findings. A structured light scanning technique is one of these methods and the most suitable for the forensic field. An assessment of the efficiency of different structured light scanners with forensic injuries is essential to validate this technique for wound documentation. The purpose of this study was to evaluate the capability of the HP structured light scanner Pro S3 for digitizing open injuries having complicated areas and depths. Fifteen simulated injuries on mannequins were scanned and assessed. Comparisons between 3D and direct wound measurements were made. The results showed that the technique was able to create detailed 3D results of the extensive injuries. Statistical significance tests revealed no difference between the two measurement methods. Because the scanner is applicable for routine work, it should be considered to confirm the same results on real cadavers and actual wounds.     

Corneal‐Smart Phone: A novel method to intelligently estimate postmortem interval

The changes of postmortem corneal opacity are often used to roughly estimate the postmortem interval (PMI) in forensic practice. The difficulty associated with this time estimate is the lack of objective means to rapidly quantify postmortem corneal changes in crime scenes. This study constructed a data analysis model of PMI estimation and implemented an intelligent analysis system for examining the sequential changes of postmortem corneal digital images, named Corneal‐Smart Phone, which can be used to quickly estimate PMI. The smart phone was used in combination with an attachment device that provided a darkroom environment and a steady light source to capture postmortem corneal images. By segmenting the corneal pupil region images, six color features, Red (R), Green (G), Blue (B), Hue (H), Saturation (S), Brightness (V) and four texture features Contrast (CON), Correlation (COR), Angular Second Moment (ASM), and Homogeneity (HOM), were extracted and correlated with PMI model. The results indicated that CON had the highest correlation with PMI (R² = 0.983). No intra/intersubject variation in CON values were observed (p > 0.05). With the increase in ambient temperature or the decrease in humidity, the CON values were increased. PMI prediction error was <3 h within 36 h postmortem and extended to about 6–8 h after 36 h postmortem. The correct classification rate of the blind test samples was 82%. Our study provides a method that combines postmortem corneal image acquisition and digital image analysis to enable users to quickly obtain PMI estimation.     

DNA in the Criminal Justice System: The DNA Success Story in Perspective,

Current figures on the efficiency of DNA as an investigative tool in criminal investigations only tell part of the story. To get the DNA success story in the right perspective, we examined all forensic reports from serious (N = 116) and high‐volume crime cases (N = 2791) over the year 2011 from one police region in the Netherlands. These data show that 38% of analyzed serious crime traces (N = 384) and 17% of analyzed high‐volume crime traces (N = 386) did not result in a DNA profile. Turnaround times (from crime scene to DNA report) were 66 days for traces from serious crimes and 44 days for traces from high‐volume crimes. Suspects were truly identified through a match with the Offender DNA database of the Netherlands in 3% of the serious crime cases and in 1% of the high‐volume crime cases. These data are important for both the forensic laboratory and the professionals in the criminal justice system to further optimize forensic DNA testing as an investigative tool.     

Soil Fungi: Their Potential use as a Forensic Tool

As a grave is an anomalous environment and differs from its surroundings, criminal investigators employ different techniques for locating, recovering, and analyzing clandestine graves. In this study were identified the fungi found in the soil under corpses in decomposition with an aim at relating the copresence of human remains and different fungal species. Were isolated the fungi in three ways: soil washing, serial dilutions, and moist chamber growth. Dichotomomyces cejpii, Talaromyces trachyspermus, Talaromyces flavus, and Talaromyces sp. were the representative species found—with those belonging to the ammonia group, whose fungi are the first in the succession of cadaver decomposition directly in the ground. The mycobiota found at the present study area clearly differs to mycobiota identified in control sample and from previously described species for other areas of Buenos Aires Province, Argentina. Further forensic examples of this type are needed to develop fully the detailed use of mycology as a forensic tool.     

腭皱法医学同一认定数字化系统的建立

目的建立腭皱法医学同一认定数字化系统并对其进行效果评价。方法在标准条件下获取腭皱的数字图像,对腭皱信息都进行采集、降噪、增强、分割、特征提取、边缘检测、信息匹配等处理,运用Matlab软件研制腭皱法医学同一认定系统,并进行效果评价。结果本研究成功建立腭皱法医学同一认定数字化系统,从匹配结果来看,正确率达到100%。结论腭皱法医学同一认定数字化系统的建立,为同一认定提供一种新的方法和途径。     

尸体检验照片的模板化编辑与标准化打印

《刑事照相制卷质量要求》既适用于各类刑事案件现场照片、治安案件和灾害事故现场照片的制卷,也适用于刑事案件检验照片和其他证据照片。因此,在司法鉴定中,尸体检验照片的制作方法应依照这一标准。＂刑事数码图像标准化技术＂应用软件用于尸体检验照片的制卷工作,可以方便和快捷地实现模板化编辑和标准化打印的目标。     

Forensic Analysis of a Contact Lens in a Murder Case

Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations.     

An inconclusive digital audio authenticity examination: a unique case

This case report sets forth an authenticity examination of 35 encrypted, proprietary-format digital audio files containing recorded telephone conversations between two codefendants in a criminal matter. The codefendant who recorded the conversations did so on a recording system he developed; additionally, he was both a forensic audio authenticity examiner, who had published and presented in the field, and was the head of a professional audio society's writing group for authenticity standards. The authors conducted the examination of the recordings following nine laboratory steps of the peer-reviewed and published 11-step digital audio authenticity protocol. Based considerably on the codefendant's direct involvement with the development of the encrypted audio format, his experience in the field of forensic audio authenticity analysis, and the ease with which the audio files could be accessed, converted, edited in the gap areas, and reconstructed in such a way that the processes were undetected, the authors concluded that the recordings could not be scientifically authenticated through accepted forensic practices.     

Public beliefs about the accuracy and importance of forensic evidence in the United States

Recent advances in forensic science, especially the use of DNA technology, have revealed that faulty forensic analyses may have contributed to miscarriages of justice. In this study we build on recent research on the general public’s perceptions of the accuracy of 10 forensic science techniques and of each stage in the investigation process. We find that individuals in the United States hold a pessimistic view of the forensic science investigation process, believing that an error can occur about half of the time at each stage of the process. We find that respondents believe that forensics are far from perfect, with accuracy rates ranging from a low of 55% for voice analysis to a high of 83% for DNA analysis, with most techniques being considered between 65% and 75% accurate. Nevertheless, respondents still believe that forensic evidence is a key part of a criminal case, with nearly 30% of respondents believing that the absence of forensic evidence is sufficient for a prosecutor to drop the case and nearly 40% believing that the presence of forensic evidence – even if other forms of evidence suggest that the defendant is not guilty – is enough to convict the defendant.     

The Kodak Syndrome: Risks and Opportunities Created by Decentralization of Forensic Capabilities

Forensic science laboratories are being challenged by the expanding decentralization of forensic capabilities, particularly for digital traces. This study recommends laboratories undertake digital transformations to capitalize on the decentralization movement, develop a more comprehensive understanding of crime and security‐relevant problems, and play a more central role in problem‐solving collaboratively with law enforcement organizations and other stakeholders. A framework for the bilateral transfer of information and knowledge is proposed to magnify the impact of forensic science laboratories on abating crime, strengthening security, and reinforcing the criminal justice system. To accomplish digital transformations, laboratories require personnel with different expertise, including investigative reasoning, knowledge codification, data analytics, and forensic intelligence. Ultimately, this study encourages managers, educators, researchers, and policymakers to look beyond the usefulness of forensic results for solving individual investigations, and to realize the value of combined forensic knowledge and intelligence for developing broader strategies to deal with crime in digitalized society.     

苏州7例杀婴案法医学分析

目的探讨和总结杀婴案的主要特征、法医学检验重点和命案现场分析要点。方法收集2008—2013年苏州市发生的7例已破杀婴案的有关资料。分析并归纳其特点。结果杀婴案嫌疑人均为受害人母亲,年龄较轻,多为未婚先孕;均为分娩后杀婴,分娩现场与杀人现场为同一地点;死亡新生儿多为机械性窒息,尸体多无衣着包裹,脐带非医源性离断,胎盘未与死亡新生儿连接。结论杀婴案法医学检验的规范化、标准化和程序化有助于案件的分析和侦破工作。     

数字图像复原技术的原理及在刑事技术中的应用

目的介绍数字图像处理技术在刑事案件复原的应用,促进该技术的发展。方法利用数字算法、滤波、几何运算等计算机图像处理技术进行复原处理。结果对案件的隐含、残缺、微弱信息,模糊图像、变形物证复原及特征显现。结论刑事数字图像复原技术在刑事技术领域有了广阔的应用前景。     

Forensic Dental Age Estimation by Measuring Root Dentin Translucency Area Using a New Digital Technique

Dentin translucency measurement is an easy yet relatively accurate approach to postmortem age estimation. Translucency area represents a two‐dimensional change and may reflect age variations better than length. Manually measuring area is challenging and this paper proposes a new digital method using commercially available computer hardware and software. Area and length were measured on 100 tooth sections (age range, 19–82 years) of 250 μm thickness. Regression analysis revealed lower standard error of estimate and higher correlation with age for length than for area (R = 0.62 vs. 0.60). However, test of regression formulae on a control sample (n = 33, 21–85 years) showed smaller mean absolute difference (8.3 vs. 8.8 years) and greater frequency of smaller errors (73% vs. 67% age estimates ≤ ±10 years) for area than for length. These suggest that digital area measurements of root translucency may be used as an alternative to length in forensic age estimation.     

应用数字图像识别系统研究正畸治疗前后腭皱形态变化

目的利用腭皱数字图像识别系统对正畸治疗前后腭皱形态匹配正确率的分析研究,为法医学中同一认定提供理论依据。方法利用正畸患者治疗前后腭皱形态数字图像,通过腭皱数字图像识别系统对图像的特征进行提取并收录到腭皱数字库,运用Matlab软件完成对腭皱形态数字图像的信息匹配处理。结果正畸治疗前后,个体性检测匹配正确率各自都达到100%。正畸治疗前后腭皱形态匹配正确率为95.67%,配对检验结果 P0.05,具有统计学意义。结论腭皱形态具有高度的个体特异性,正畸治疗后腭皱形态会发生多种变化,但对同一认定的影响不大。腭皱形态识别为法医学同一认定提供一种新的方法和途径。     

Unanalyzed evidence in law-enforcement agencies

Research Summary This study investigated forensic evidence processing in a nationally representative sample of state and local law-enforcement agencies (n = 3,153). For a 5-year period, agencies reported that 14% of all unsolved homicides (an estimated 3,975 cases) and 18% of all unsolved rapes (an estimated 27,595 cases) contained forensic evidence that had not been submitted to a forensic crime laboratory for analysis. Approximately 40% of these unanalyzed homicide and rape cases were reported to have contained DNA evidence. The lack of a suspect in the case was the most frequently cited reason for not submitting forensic evidence for analysis. Policy Implications Despite an increased diffusion of knowledge regarding the value of forensic evidence in the prosecution and defense of criminal cases, the investigative capabilities of forensic science are not being realized by law enforcement. Additional training for law enforcement on the use of forensic science to develop investigative leads is critical, as is the creation of departmental policies that prioritize and streamline the analysis of forensic evidence for homicide and rape cases—even in “no-suspect” cases. Ensuring adequate resources and information sharing for forensic processing especially of violent crimes, is also critical.     

Photoshop图像分析法在不规则瘢痕鉴定中应用

目的 探讨photoshop图像分析方法在不规则瘢痕鉴定中的应用价值.方法 用photoshop图像分析方法和数格法对30种不规则瘢痕进行面积计算,并对其准确性和实用性进行比较.结果 photoshop图像分析方法与数格法所计算出的面积之间无明显差异(P =0.960 7),而在检测时间和过程等方面photoshop图像分析方法明显优于数格法.结论 photoshop图像分析法用于不规则瘢痕的面积计算,具有既准确又节省时间的优点,可以在不规则瘢痕的法医学鉴定中选择使用.