浅谈刑事影像数字化的重要性

1 刑事影像数字化的必要性 刑事影像,包括刑事照相、刑事录相和刑事图像处理,是刑事技术的重要组成部分,在揭露、证实和打击犯罪斗争中起着非常重要的作用。但是长期以来刑事影像工作一直沿用着古老、传统的方式、方法进行     

浅析刑事影像技术在侦查、调查取证工作中的重要作用

本文叙述了刑事影像技术是运用影像方法对发生案件的地点和遗留犯罪痕迹、物证的场所,按照现场勘查的规定和办案工作的要求,把现场状况及痕迹物证的特点、位置等,如实地拍照、拍摄下来,为研究案情性质,分析作案手段,进行现场实验提供资料,为技术检验、鉴定提供条件,为起诉、审判提供证据。     

全波段CCD系统在刑事影像技术中的应用

全波段CCD系统可在波长200-1200纳米光谱范围进行摄影,包括紫外线、可见光和红外线。它可将不可见光图像实时转化为可见光图像,并可实现低照度情况下微弱信号的采集以及高质量图像的采集和处理,集痕迹检验、文件检验、数字照相和图像处理于一体。本文介绍了全波段CCD系统的结构、特点与在刑事影像技术中的应用。     

刑警的旗帜在地震废墟上高高飘扬

“5．12”地震发生后，公安部刑侦局迅速派出专家组．并协调湖南、重庆、贵州．云南四省市优选160名法医和影像技术专业人员．组成40个战斗小组赶赴灾区开展地震遇难者遗体检验识别工作。前方专家组和刑事科学技术专业队成员在余震、塌方、滑坡等恶劣条件下日夜奋战在抗震一线，扎实做好地震遇难者遗体检验识别工作。     

公安部物证鉴定中心专业学术会议资讯

为了提高刑事技术人员现场勘查能力和检验鉴定水平,推广交流新技术、新方法,促进刑事技术发展进步,公安部物证鉴定中心将于2015年第三、四季度分别召开第五届全国指纹学学术交流会、全国影像检验技术学术交流会,第三届全国电子物证检验技术交流会和第四届全国公安机关DNA数据库建     

影响刑事照相清晰度的因素及对策

刑事照相的影像清晰度要求较高,良好的清晰度是图像资料成为刑事案件证据的必要条件,是物证检验鉴定技术工作顺利进行的重要保证。提高清晰度,需从以下几个方面进行。 1 照明因素 一般现场照相对光线、照明无特殊要求,只要能够完整地、客观地、形象地、真实地反映现场场景和具体事物的形态、状态就行。但拍摄痕迹物证最好在暗室进行。     

《刑事技术》投搞须知

《刑事技术》是由公安部物证鉴定中心主办,国内外公开发行的综合性学术期刊,主要报道法庭科学技术方面的研究成果和与其相关的新技术、新观点、实践经验及典型案例分析等。涉及的专业有法医病理损伤学、法医人类学、法医DNA遗传学、毒物分析、毒品检验、痕迹检验、文件检验、指纹个体识别、微量物证理化检验、枪弹爆炸物检验、视频影像分析检验,声纹分析、电子物证检验、书写材料和书写时间检验等。     

《刑事技术》投稿须知

《刑事技术》是由公安部物证鉴定中心主办,国内外公开发行的综合性学术期刊,主要报道法庭科学技术方面的研究成果和与其相关的新技术、新观点、实践经验及典型案例分析等。涉及的专业有法医病理损伤学、法医人类学、法医DNA遗传学、毒物分析、毒品检验、痕迹检验、文件检验、指纹个体识别、微量物证理化检验、枪弹爆炸物检验、视频影像分析检验,声纹分析、电子物证检验、书写材料和书写时间检验等。     

《刑事技术》投搞须知

《刑事技术》是由公安部物证鉴定中心主办,国内外公开发行的综合性学术期刊,主要报道法庭科学技术方面的研究成果和与其相关的新技术、新观点、实践经验及典型案例分析等。涉及的专业有法医病理损伤学、法医人类学、法医DNA遗传学、毒物分析、毒品检验、痕迹检验、文件检验、指纹个体识别、微量物证理化检验、枪弹爆炸物检验、视频影像分析检验,声纹分析、电子物证检验、书写材料和书写时间检验等。     

《刑事技术》投稿须知

《刑事技术》是由公安部物证鉴定中心主办,国内外公开发行的综合性学术期刊,主要报道法庭科学技术方面的研究成果和与其相关的新技术、新观点、实践经验及典型案例分析等。涉及的专业有法医病理损伤学、法医人类学、法医DNA遗传学、毒物分析、毒品检验、痕迹检验、文件检验、指纹个体识别、微量物证理化检验、枪弹爆炸物检验、视频影像分析检验,声纹分析、电子物证检验、书写材料和书写时间检验等。     

Photographic Image Comparison of Vegetation

Images and videos are common types of evidence in crime scene investigations and laboratory analysis. Images may be taken by the suspect and/or by crime scene investigators and may serve as crucial elements in forensic laboratory analysis. Forensic photographic image comparison is the process of comparing one or more objects or persons in photographs/images when at least one image is known to be related to a crime. The forensic examiner usually compares the images in order to determine whether or not an association between the exhibits in the images can be made. This paper proposes an extension to the currently prevalent photographic image examination method. The extension introduces comparison of landscape and vegetation over time. It is revealed that similarities between images may still be found between the period of time the suspect photograph was taken and the period the crime scene investigator took the photograph from the same area. In this case report, two suspects to be involved in growing a marijuana field were arrested by the police. The forensic experts were asked to examine images taken by the crime scene investigators and to compare them to the images found in the suspects’ phones. They then tried to determine whether the suspects could be linked to the specific locations. While applying techniques derived from morphological comparison methodologies, the plants at the scene provided significant additional information. A tree trunk, branches, and twigs on a hedge in the photographs revealed specific individual characteristics that led the examiner to reach a conclusive decision.     

多源图像融合技术及其在公安刑事摄影工作中的应用

近年来,多源图像融合技术的应用越来越多,它可以将同一场景以不同成像方式或者不同成像时间获得的不同图像融合为一幅图像。这种技术可以综合多张照片的信息量,提高视觉感知,便于进行计算机的处理,因此,可在公安刑事摄影工作中用于对疑难指纹、立体痕迹、强反光客体痕迹、高逆光现场照片等的拍摄和处理,从而最大程度的准确反映被摄景物的实际情况。     

Fire investigation and ignitable liquid residue analysis--a review: 2001-2007

Next to natural disasters fires cause some of the greatest losses to property and human life around the world. Arson, the deliberate setting of a fire to destroy property or to take a human life, is one of the most difficult crimes to investigate because much of the evidence at the scene is destroyed by the fire. Fortunately, the science of fire investigation is not static and more information to help investigators determine the origin and cause of a fire through careful examination of the scene and laboratory analysis of fire debris is published every year. This review article provides an overview of the scientific literature describing research and best practices in the fields of fire scene investigation as well as ignitable liquid residue analysis. This review is a compilation of articles published between late 2001 and early 2007. Conference proceedings for which full papers have not been published were intentionally excluded from this review. Some of the information contained in this review was presented at the 14th Interpol Forensic Science Symposium held in Lyon, France in October 2004.     

The Role of Forensic Botany in Solving a Case: Scientific Evidence on the Falsification of a Crime Scene

Forensic botany can provide useful information for pathologists, particularly on crime scene investigation. We report the case of a man who arrived at the hospital and died shortly afterward. The body showed widespread electrical lesions. The statements of his brother and wife about the incident aroused a large amount of suspicion in the investigators. A crime scene investigation was carried out, along with a botanical morphological survey on small vegetations found on the corpse. An autopsy was also performed. Botanical analysis showed some samples of Xanthium spinosum, thus leading to the discovery of the falsification of the crime scene although the location of the true crime scene remained a mystery. The botanical analysis, along with circumstantial data and autopsy findings, led to the discovery of the real crime scene and became crucial as part of the legal evidence regarding the falsity of the statements made to investigators.     

Hyperspectral imaging in forensic science: An overview of major application areas

Analysis of evidence is a challenge. Crime scene materials are complex, diverse, sometimes of an unknown nature. Forensic science provides the most critical applications for their examination. Chemical tests, analytical methods, and techniques to process the evidence must be carefully selected by the forensic scientist. Ideally, it may be interpreted, analyzed, and judged in the original context of the crime scene. In this sense, hyperspectral imaging (HSI) has been employed as an analytical tool that maintains the integrity of the samples/objects for multiple and sequential analysis and for counter-proof exams. This paper is an overview of forensic science trends for the application of HSI techniques in the last ten years (2011–2021). The examination of documents was the main area of exploration, followed by bloodstain analysis aging process; trace analysis of explosives and gunshot residue. Chemometric tools were also addressed since they are crucial to obtain the most important information from the samples. There are great challenges in applying HSI in forensic science, but there have been clear technological and scientific advances, and a solid foundation has been built for the use of HSI in real-life cases.     

Explosion Scene Forensic Image Interpretation

Image interpretation is an important aspect in the field of forensic science; however, it is seldom reported how to use these techniques in explosion scene forensic investigations. On 12 August 2015, a series of explosions killed 165 people and injured hundreds more at a container storage station at the Port of Tianjin. In this study, we applied image interpretation methods to determine the seat of the explosion by analyzing low‐quality video clips of the event. The interpretation fits well with recently published standard operating procedures, including the hypothesis, evaluation, inference, and confirmation. Image processing was adopted to enhance the images while the explosion scene was reconstructed with the same images. Some important features were extracted and utilized to distinguish whether the flashes were caused by reflection or a real blast. We reveal the real explosion location, which guides the overall investigation. The results indicate that image interpretation is a powerful tool for forensic investigators to analyze low‐quality images in complicated explosions or fire accidents.     

Intentional Homicide: A Fifteen-Year Study (2000–2014) at the Department of Forensic Medicine,University of Rome “Sapienza”

This study analyzes postmortem records from 260 homicide cases autopsied by the Department of Forensic Medicine in Rome from 2000 to 2014. The victims were mainly males (74%) and young (61% aged from 21 to 50 years). Although the victims were mostly Italians, the number of foreign victims (33%) has increased since 1990, primarily due to immigration. The offenders frequently used firearms (39%), particularly in multiple murders. An increase in blunt (20%) and sharp force (32%) weapons was also seen. The primary crime scene was residential (42%), and the head was the most frequently injured body region. Male victims occurred frequently in the context of organized crime (7.6%). In family or intimate-sexual relationships, women were the majority of victims (8%). Forensic pathologists play an important role during investigation. They should consider all the information available to them, including autopsy information, crime scene information, and crime investigation data.     

The Effect of Image Quality and Forensic Expertise in Facial Image Comparisons

Images of perpetrators in surveillance video footage are often used as evidence in court. In this study, identification accuracy was compared for forensic experts and untrained persons in facial image comparisons as well as the impact of image quality. Participants viewed thirty image pairs and were asked to rate the level of support garnered from their observations for concluding whether or not the two images showed the same person. Forensic experts reached their conclusions with significantly fewer errors than did untrained participants. They were also better than novices at determining when two high‐quality images depicted the same person. Notably, lower image quality led to more careful conclusions by experts, but not for untrained participants. In summary, the untrained participants had more false negatives and false positives than experts, which in the latter case could lead to a higher risk of an innocent person being convicted for an untrained witness.     

The application of CT for 3D visualization of concealed bodies

In forensic radiology, computed tomography (CT) is often used as a medical imaging technique to identify the cause and manner of death of deceased victims of a possible crime. In this study, medical imaging is used to examine concealed bodies and packaging materials. Medical imaging techniques, mainly CT scan, were used to scan packaged or concealed bodies inside containers to identify clues and evidence indicating whether a crime might have been committed. Also, scene integrity and scene safety along with a systematic search for relevant evidentiary items value were considered.Eighteen concealed bodies that had been assessed using medical imaging techniques between 2010 and 2018 at the request of the Dutch National Police were selected. The file records of each case contained imaging data, a photographic record of the unpacking procedure, a list of all items and traces found in the package, and the forensic pathology report. The images were assessed with respect to the different aspects of the case and through a systematic approach.The packages included adult males, adult females, newborn infants, and animals. All human cases were related to criminal offences. In nine adult cases, evidence of a possible violent death could be determined using CT imaging. The cause of death in newborn infants, however, could not be determined. In cases of dismemberment, the completeness of the body could be determined by CT imaging, and the cutting surfaces of bones could be matched on CT images. Regarding scene safety and integrity, in this study all relevant macroscopic items were detected on the CT images.The CT-scans were supplemented with fiduciary markers to better map CT data with the real objects. This information in combination with 2D and 3D images provided the forensic investigator with information on how to unwrap the package layer by layer and help determine different types of packaging materials. Different textiles could not always be identified. The orientation of the body within the packages was provided in all cases, and advice could be given on the optimal approach to access the contents. The overall detection rate of items was 78%.This is one of the first studies to illustrate the contribution of medical imaging, specifically CT scan, to the analysis of concealed bodies and packaging materials prior to unpacking. This demonstrates its contribution to a systematic approach of the investigation by ensuring the safety and health of the investigator while documenting and maintaining the integrity of the crime scene. Imaging also provides information that can be helpful to determine whether a crime might have been committed and reducing the risk of damaging a concealed body. Medical imaging also provides the forensic investigator with information to draw up a workplan prior to unpacking, minimising loss of evidence and determining whether different forensic specialists (e.g., digital or DNA) are needed. It is therefore strongly recommended to use medical imaging, especially CT scanning, before opening a package containing a concealed body.     

Automatic forensic face recognition from digital images.

Digital image evidence is now widely available from criminal investigations and surveillance operations, often captured by security and surveillance CCTV. This has resulted in a growing demand from law enforcement agencies for automatic person-recognition based on image data. In forensic science, a fundamental requirement for such automatic face recognition is to evaluate the weight that can justifiably be attached to this recognition evidence in a scientific framework. This paper describes a pilot study carried out by the Forensic Science Service (UK) which explores the use of digital facial images in forensic investigation. For the purpose of the experiment a specific software package was chosen (Image Metrics Optasia). The paper does not describe the techniques used by the software to reach its decision of probabilistic matches to facial images, but accepts the output of the software as though it were a 'black box'. In this way, the paper lays a foundation for how face recognition systems can be compared in a forensic framework. The aim of the paper is to explore how reliably and under what conditions digital facial images can be presented in evidence.