集散型计算机指纹信息网络管理与应用

计算机网络技术的广泛应用 ,为指纹信息的共享、异地远程指纹查询比对提供了新的更有效的途径。在侦查破案中发挥着积极作用。江苏省公安厅刑侦局从 2 0世纪 90年代开始了集散型指纹信息网络管理方面的研究 ,1997年起与清华大学合作研制开发《ＣＡＦＩＳ指纹远程网络查询管理系统》 ,到目前为止 ,已形成了以省厅为中心 ,各市为网点 ,县市区建查询终端的覆盖全省的集散型计算机指纹信息网络化管理系统 ,实践证明 ,系统的建设为我省侦查破案提供更为宽阔信息渠道。1　基本概念集散型指纹信息网络管理是运用现有的公安数据通信网络 ,将分散各地…     

关于指纹自动识别系统数据传输模式的探讨

近年来 ,以省厅指纹中心大型数据库为依托 ,以公安通讯网络为数据传输平台的地域指纹信息网络实现了巨大的破案效益。但是 ,由于公安网络带宽、稳定性、计算机病毒、远程用户系统状态及人员操作水平等因素造成的信息共享障碍还时有发生。因此 ,作为全省指纹资料存储、查询和管理部门的省厅指纹中心 ,如何建立若干备用传输通道 ,以保证全省二、三级远程用户在各种情况下指纹数据的即时传输 ,就成为一个不容忽视的问题。1　指纹自动识别系统后台远程数据传输模式及网络通信间隔性阻断对远程查询服务的影响指纹自动识别系统 (COGENTCAFIS)…     

异地数码指纹图像查询

我市于 2 0 0 1年 5月购买了Ｃａｆｉｓ指纹自动识别查询系统 ,在实际工作过程中 ,经常遇到下属各县、市局和分局刑事技术三级点的同志 ,在基层辖区勘查完刑事案件现场后 ,将在现场提取的现场指纹 ,驱车送来市局查询 ,很大程度上影响了侦察破案的工作效率。为了解决这个问题 ,我们尝试了将数码指纹图像输入系统进行查询比对 ,成功地在局域网内利用网络传送数码指纹图像至指纹系统 ,进行异地数码指纹图像查询 ,这样就解决了基层单位一时配置不了指纹远程查询工作站 ,又急需指纹自动识别系统提高工作效率的现实问题 ,由于传统的光学相机要对拍…     

CAFIS指纹系统远程查询的应用和管理

CAFIS指纹系统是我国自行开发研制的指纹自动识别系统,它作为一种高科技成果,在刑侦领域得到广泛的应用,在打击犯罪,揭露犯罪的斗争中取得了明显成效。 随着改革开放和经济的发展,我国刑事犯罪出现了许多新的特点,跨区域流窜犯罪和外来人口犯罪增多,侦破工作中,指纹异地查询,指纹信息异地交流等工作随之增多。因此,实现指纹远程查询比对,使信息资源共享,提高公安机关的办案能力和工作效率已成为指纹自动识别系统发展的必然趋势。     

浅谈指纹自动识别系统的发展趋势

目前全国大部分省市公安机关都建立了省级指纹自动识别系统 ,主要有美国ＣＯＧＥＮＴ、日本ＮＥＣ、北大高科等指纹系统 ,管理容量在 5 0万至 30 0万之间 ,不少地市已建立了管理容量在几万至几十万的中型指纹自动识别系统 ,部分县级公安机关建立了指纹远程查询工作站或小型指纹自动识别系统。指纹自动识别系统代替了人工管理指纹并辅助指纹鉴定 ,大大提高了指纹检索比对的速度 ,减少了人为因素的影响 ,在刑侦工作中已成为不可缺少的技术装备和揭露、打击犯罪行之有效的技术手段。笔者多年从事指纹自动识别系统工作 ,对指纹自动识别系统的应…     

浙江指纹自动识别系统建设一瞥

1996年,浙江省公安厅刑警总队在“科技强警、信息强侦”思想的指引下,要求全省各级刑侦部门统一组建指纹自动识别系统,并以此为切入点,加大科技投入,积极推进刑事技术和刑侦信息化建设。1996—1998年间,省厅及各市相继建立起一套相对独立的单机系统;1999年,省厅与北京大学合作,成功开发出指纹远程比对系统,从此,全省指纹系统逐步向网络化迈进;迄今为止,省公安厅建立了总库,11个市全部建立了分库,92个县建立了217套远程比对工作站,形成“二级建库、三级查询”的运行模式。自建立指纹系统以来,全省利用系统破案效益日益显著,破案总数连年翻番。1996年全省直接查破案件仅5起;1997年直接查破168起;1998年直接查破413起;1999年直接查破1273     

加强基础业务建设把好指纹收集质量关

几年来,江苏省指纹信息管理工作始终坚持“科教强警”的指导思想,强化现代科技意识,狠抓指纹基础业务管理工作,使全省指纹信息管理的整体水平提高到了一个新的层次。目前,全省已有11个省辖市和27个县（市）建立了指纹自动识别系统,省厅与9个省辖市实现了指纹异地远程联网查询。全省指纹系统建设之所以能得到迅速发展,与各级部门密切配合,精心组织,强化基础工作,狠抓各项工作措施、制度落实是密不可分的。     

充分发挥"系统"效益

厦门地处我国东南沿海 ,是经济特区之一 ,拥有常住人口 12 5余万人 ,外来人口 80余万人 ,年发刑案从过去 6 0 0 0余起增到 170 0 0余起 ,为利用指纹档案破案 ,我们于 1997年 3月引进“北大方正指纹识别系统”。 2 0 0 1年元月根据实战需要对原系统进行了扩容改造 ,用“Ｃｏｇｅｎｔ指纹识别系统”取代原来的系统 ,并将系统容量扩至 5 0万人指纹的库容 ,同时建立了 7个远程指纹比对工作站。目前实际建库为十指档案库 12万余人份 ,现场指纹 2万余枚。 5年来 ,我们注意不断总结经验 ,拓展思路 ,根据指纹系统运作的最佳条件要求 ,逐步规范指纹管…     

浅谈文档信息在指纹识别系统中的应用

目前，尚没有全同统一的指纹识别系统，各省市级指纹识别系统往往版本各一，在系统难以统一的情况下，公安部研发的指纹信息平台起到了一个桥梁作用，通过它可以实现指纹数据及其文档信息的交换和查询，为指纹文档信息的应用提供了信息共享，资源最大化利用的平台。     

影响指纹自动识别系统运行效益的原因和对策

目前,全市已建成由市局中心库,10个并行处理器,19个远程工作站组成的指纹网络比对系统。建库和运行已形成“二级建库,三级查询”的模式。现已入库十指纹14万余份,现场指纹1.6万枚。系统效益十分明显,直接认定数由1998年的8起,2000年的600余起,猛增至2002年的1060起。但在运行指纹自动识别系统(以下称“系统”)充分发挥其总体效益上,仍存在一定差距,为此,笔者提出了一些改进和加强的对策和措施,讨论如下:1影响“系统”效益的主要问题(1)现场指纹在采集数量和质量上都不尽人意。特别是现场指纹的质量问题,主要是指提取的现场指纹与犯罪的内在…     

The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings

Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.     

Autopsy Fingerprint Technique Using Fingerprint Powder

The collection of high‐quality fingerprints is an important component of routine forensic autopsies and represents one of the several potential methods for identifying a decedent. Fingerprint collection at autopsy frequently employs a manual method using fingerprint ink and cards, although some offices use digital‐scanning equipment. While these methodologies are adequate in most circumstances, this study introduces an alternative method using fingerprint powder and adhesive labels. The method is quick, easy to perform, and cost‐effective and provides the additional advantage of an adhesive label that easily conforms to the finger, palm, or foot which reduces smudging of prints in individuals with rigor mortis, skin slippage, or decomposition compared to more traditional autopsy fingerprint collection techniques. The prints can then be easily stored, either in hard‐copy form or scanned to make a digital record.     

Estimation of age-at-death for adult males using the acetabulum, applied to four Western European populations

Methods to estimate adult age from observations of skeletal elements are not very accurate and motivate the development of better methods. In this article, we test recently published method based on the acetabulum and Bayesian inference, developed using Coimbra collection (Portugal). In this study, to evaluate its utility in other populations, this methodology was applied to 394 specimens from four different documented Western European collections. Four strategies of analysis to estimate age were outlined: (a) each series separately; (b) on Lisbon collection, taken as a reference Coimbra collection; (c) on Barcelona collection, taken as a reference both Portuguese collections; and (d) on London collection taken as reference the three Iberian collections combined. Results indicate that estimates are accurate (83-100%). As might be expected, the least accurate estimates were obtained when the most distant collection was used as a reference. Observations of the fused acetabulum can be used to make accurate estimates of age for adults of any age, with less accurate estimates when a more distant reference collection is used.     

Testing for Potential Contextual Bias Effects During the Verification Stage of the ACE‐V Methodology when Conducting Fingerprint Comparisons*

Abstract: This study was conducted to assess if fingerprint specialists could be influenced by extraneous contextual information during a verification process. Participants were separated into three groups: a control group (no contextual information was given), a low bias group (minimal contextual information was given in the form of a report prompting conclusions), and a high bias group (an internationally recognized fingerprint expert provided conclusions and case information to deceive this group into believing that it was his case and conclusions). A similar experiment was later conducted with laypersons. The results showed that fingerprint experts were influenced by contextual information during fingerprint comparisons, but not towards making errors. Instead, fingerprint experts under the biasing conditions provided significantly fewer definitive and erroneous conclusions than the control group. In contrast, the novice participants were more influenced by the bias conditions and did tend to make incorrect judgments, especially when prompted towards an incorrect response by the bias prompt.     

Faux Blood Fingermark on Pistol: Latent Fingerprint Developed by Whole Blood

We present a case of a faux blood fingermark, wherein a natural latent fingerprint on the pistol at the crime scene was enhanced by the whole blood of the victim. A male was shot to death. The crime scene investigator did not find any blood fingermark during the collection of evidence, but a blood fingerprint was noticed in the firearms examination. We identified that the fingerprint was of the victim; a series of experiments on the nonporous substrate were then conducted; the death in this case was classified as a suicide. The phenomenon is interesting, and thus, calls for attention of the forensic community.     

对尸体指纹种类认定依据的研究

指纹状态属性的认定是当前指纹鉴定工作的一个新课题。指纹鉴定中的押名指印一般情况下都是押名人生前主动捺印形成的,但在实践中有时会出现作案人为了扰乱侦查视线、逃避惩罚或获取某种利益,而利用尸体指纹捺印伪造死者生前的押名指印的情况,因此对尸体指纹种类认定的研究将有助于侦查破案或对事实的确认。早期尸体现象是尸体指纹具备区别于活体指纹的特定性和相对稳定性的关键,再加上指纹本身所具有的反映性,这＂三性＂共同构成了尸体指纹种类认定的科学基础,为判定尸体指纹提供了理论依据。对于尸体指纹的研究,一方面须得益于尸体指纹捺印外观特征规律的深入总结,而另一方面也需要将微观层面的尸体指纹汗孔特征作为研究的切入点。总之,研究的最终目的就是提高尸体指纹种类认定的科学可靠性,进而使这一认定结论能作为一种科学的鉴定意见在诉讼中运用。     

Leaving timing-channel fingerprints in hidden service log files

Hidden services are anonymously hosted services that can be accessed over an anonymity network, such as Tor. While most hidden services are legitimate, some host illegal content. There has been a fair amount of research on locating hidden services, but an open problem is to develop a general method to prove that a physical machine, once confiscated, was in fact the machine that had been hosting the illegal content. In this paper we assume that the hidden service logs requests with some timestamp, and give experimental results for leaving an identifiable fingerprint in this log file as a timing channel that can be recovered from the timestamps. In 60 min, we are able to leave a 36-bit fingerprint that can be reliably recovered. The main challenges are the packet delays caused by the anonymity network that requests are sent over and the existing traffic in the log from the actual clients accessing the service. We give data to characterize these noise sources and then describe an implementation of timing-channel fingerprinting for an Apache web server based hidden service on the Tor network, where the fingerprint is an additive channel that is superencoded with a Reed–Solomon code for reliable recovery. Finally, we discuss the inherent tradeoffs and possible approaches to making the fingerprint more stealthy.     

Measuring the Rarity of Fingerprint Patterns in the Dutch Population Using an Extended Classification Set

Latent print examiners often use their experience and knowledge to reach a conclusion on the identity of the source. Their conclusion is primarily based on their personal opinion on the rarity of the matching fingerprint features. Fingerprint patterns, if present, can play a significant role in the final assessment of a match. The authors believe that statistical data on the rarity of fingerprint patterns strengthens the subjective evaluation of the corresponding information. In order to provide fingerprint examiners with additional numerical support, fingerprint patterns were manually classified in a set of 24,104 fingerprints. In this study the frequencies of occurrence of 35 different fingerprint patterns have been obtained. The frequency data presented in this study can be used in the ACE‐V process applied in forensic casework, allowing for the assessment of the evidential strength related to a specific fingerprint pattern type.     

NFIQ 2.0用于指纹质量控制的可行性及方法

目的测试NFIQ 2.0标准计算指纹质量评分模块在活体采集和油墨捺印指纹质量控制上的可靠性,研究利用NFIQ 2.0指纹分值综合判断指纹质量的可行性和在实际工作中的使用方法。方法一是利用NFIQ 2.0模块接口程序结合VS2015 C#编程语言制作指纹质量评分软件。二是记录20张指纹图片放置在采集框上、下、左、右、中五个位置时NFIQ 2.0的分值,计算平均偏差、最大偏差和相对偏差。三是对在指纹数据库中随机选出的1334枚活体采集和油墨捺印指纹(8位灰度、500 dpi BMP格式指纹图片)进行评分,将得出的分值与通过人工检查该1334枚指纹在指纹系统中自动提取的特征所计算的特征准确率,形成线条图并制作拟合线,通过线条图和拟合线研究NFIQ 2.0分值与特征准确率之间存在的关系。结果从平均偏差、最大偏差和相对偏差分析,指纹图片放置位置对NFIQ 2.0分值的影响很小。利用线条图和拟合线进行统计时,NFIQ 2.0分值与特征准确率之间呈现出一定的对应关系,NFIQ 2.0分值高的指纹,系统自动提取的特征准确性相对较高,反之相对较低。并且,分值在41~100之间时,特征准确率稳定在80%以上。结论NFIQ 2.0标准计算指纹质量评分模块可以用于大批量活体采集和油墨捺印指纹的辅助质量检测,在实际工作中可将NFIQ 2.0模块嵌入活体采集软件和指纹系统档卡扫描中,设定合理的阈值,对提高指纹采集的质量检测效率和提升指纹采集质量将有较大帮助。     

Particle characteristics of trace high explosives: RDX and PETN

The sizes of explosives particles in fingerprint residues produced from C-4 and Semtex-1A were investigated with respect to a fragmentation model. Particles produced by crushing crystals of RDX and PETN were sized by using scanning electron microscopy, combined with image analysis, and polarized light microscopy was used for imaging and identifying explosive particles in fingerprint residues. Crystals of RDX and PETN fragment in a manner that concentrates mass in the largest particles of the population, which is common for a fragmentation process. Based on the fingerprints studied, the particle size to target for improving mass detection in fingerprint residues by ion mobility spectrometry (IMS) is > or = 10 microm in diameter. Although particles smaller than 10 microm in diameter have a higher frequency, they constitute < 20% of the total mass. Efforts to improve collection efficiency of explosives particles for detection by IMS, or other techniques, must take into consideration that the mass may be concentrated in a relatively few particles that may not be homogeneously distributed over the fingerprint area. These results are based on plastic-bonded explosives such as C-4 that contain relatively large crystals of explosive, where fragmentation is the main process leading to the presence of particles in the fingerprint residues.