Toward multidimensional information: A derivatization-free UHPLC-QqQ MS/MS method for amino acid components of fingerprint

The analysis of fingerprint chemical composition is a meaningful way to excavate the multidimensional information of fingerprint, including the donor profiling information and the age of a fingerprint, which broadens the evidential values of fingerprint, especially for the partial and distorted fingerprint. But the research remains still in the pilot phases or is ongoing. Amino acids are the dominant organic substances in latent sweat fingerprint and influenced by many donor factors. Hence, their content reflects personal information of donors. Forensic science will be revolutionized if suspects can be individualized by their amino acid content. The diverse nature, distinct physicochemical properties, and ultra-micro levels of amino acids present in fingerprints make it hard to detect. A high sensitivity method for detecting and quantifying multiple amino acid components is required. UHPLC-QqQ MS/MS offers high sensitivity, high separation, simultaneous multicomponents detection, and no derivatization, making it an ideal method for detecting and analyzing amino acids in fingerprints. Therefore, in this study, we propose and validate an efficient UHPLC-QqQ MS/MS method for the extraction and analysis of 13 amino acids from fingerprint. We compared the results of amino acids of 10 different substrates and found that the inherent amino acids in most porous substrates would have been extracted along with the fingerprint amino acids, making them unsuitable for quantitative amino acid analysis. Instead, plastic sheets are ideal substrates for laboratory studies. Then, extensive experiments were conducted among 30 donors for multidimensional information analysis. The type of samples analyzed were eccrine-rich fingerprints. A Binary Logistic Regression (BLR) model was developed, and the female and male donors were successfully differentiated by amino acids in fingerprints. Two other mathematical models were also developed to verify the accuracy, and all three different mathematical models were able to identify donors of different genders with over 90% accuracy. This demonstrates that amino acids have the potential to provide more information for donors as metabolic markers. In the future, we will conduct a series of experiments to analyze more multidimensional information for individual identification by amino acid content in the fingerprint.     

Refreshing the Aged Latent Fingerprints with Ionizing Radiation Prior to the Cyanoacrylate Fuming Procedure: A Preliminary Study

One of the crucial factors determining the cyanoacrylate deposit quality over latent fingerprints appeared to be the extent of the humidity. This work focuses on the enhancement/refreshment of age‐degraded latent fingerprints by irradiating the samples with UV, X‐ray, or thermal neutrons prior to the cyanoacrylate (CA) fuming. Age degradation of latent fingerprints deposited on glass surfaces was examined through the decrease in the number of characteristic minutiae counts over time. A term “critical day” was introduced for the time at which the average number of identifiable minutiae definitions drops to one‐half. Fingerprints older than their “critical day” were exposed to either UV, X‐ray, or thermal neutrons. Identical reference samples were kept unexposed. All samples, both reference and irradiated, were developed during a single CA fuming procedure. Comparative latent fingerprint analysis showed that exposure to ionizing radiation enhances the CA fuming, yielding a 20‐30% increase in average minutiae count.     

Integrated DNA and Fingerprint Analyses in the Identification of 60‐Year‐Old Mummified Human Remains Discovered in an Alaskan Glacier

Abstract: This report describes the identification of a merchant mariner who perished in 1948 when Northwest Airlines Flight 4422, a DC‐4 carrying 24 seamen and six crew members crashed into Mount Sanford, Alaska. Fifty‐one years later, a human forearm and hand were found close by the wreckage of the plane, prompting identification efforts using DNA and fingerprints. There were significant challenges to both the fingerprint and DNA analyses. The hand was badly desiccated, making fingerprint friction‐ridge detail almost invisible and the remains had been embalmed upon discovery, making DNA amplification difficult. We present the results of an interdisciplinary approach that successfully addressed these challenges and ultimately led to the identification of the remains. These efforts relied on efficient fingerprint rejuvenation and imaging techniques that improved print resolution, as well as new DNA extraction techniques optimized for aggressively embalmed remains.     

Second‐hand Emotion? Exploring the Contagion and Impact of Trauma and Distress in the Asylum Law Context

Applicants' accounts of experiences of fear, trauma, violence, and persecution are central to the process of claiming asylum. These narratives are, at a human level, primed to provoke emotional responses, not only in the narrator but also in those to whom the account is relayed. In this article, we explore the vectors of emotionality that permeate asylum decision‐making in the United Kingdom, focusing particularly on the risk faced by the professionals involved of suffering vicarious trauma. More specifically, based on a series of 104 semi‐structured interviews with asylum stakeholders and observation of 48 appeals to the Immigration and Asylum Chamber of the First‐tier Tribunal, this article identifies the adoption by legal and quasi‐legal professionals of emotional coping strategies – of detachment and denial of responsibility – that risk being deployed in maladaptive ways that jeopardize the prospects for justice.     

The impact of human-technology cooperation and distributed cognition in forensic science: biasing effects of AFIS contextual information on human experts

Experts play a critical role in forensic decision making, even when cognition is offloaded and distributed between human and machine. In this paper, we investigated the impact of using Automated Fingerprint Identification Systems (AFIS) on human decision makers. We provided 3680 AFIS lists (a total of 55,200 comparisons) to 23 latent fingerprint examiners as part of their normal casework. We manipulated the position of the matching print in the AFIS list. The data showed that latent fingerprint examiners were affected by the position of the matching print in terms of false exclusions and false inconclusives. Furthermore, the data showed that false identification errors were more likely at the top of the list and that such errors occurred even when the correct match was present further down the list. These effects need to be studied and considered carefully, so as to optimize human decision making when using technologies such as AFIS.     

Does contextual information bias bitemark comparisons?

A growing body of research suggests that the interpretation of fingerprint evidence is open to contextual bias. While there has been suggestion in the literature that the same might apply to bitemarks – a form of identification evidence in which a degree of contextual information during the comparison phase is generally unavoidable – there have so far been no empirical studies to test this assertion. We explored dental and non-dental students' ability to state whether two bitemarks matched, while manipulating task ambiguity and the presence and emotional intensity of additional contextual information. Provision of the contextual information influenced participants' decisions on the ambiguous bitemarks. Interestingly, when participants were presented with highly emotional images and subliminally primed with the words ‘same’ and ‘guilty’, they made fewer matches relative to our control condition. Dental experience also played a role in decision-making, with dental students making more matches as the experiment progressed, regardless of context or task ambiguity. We discuss ways that this exploratory research can be extended in future studies.     

论情绪的刑法评价

情绪对刑事责任的影响主要表现为强烈情绪对刑事责任能力的影响和引发情绪的被害人过错对犯罪动机的影响。对情绪进行刑法评价的考察因素主要有:刺激因素的范围与真实性、情绪的强度以及情绪行为的指向与持续性。在刑事立法上,可采取两种方式对情绪加以评价:总括式立法,在刑事责任能力条款中增设情绪犯罪责任的规定;分散式立法,在具体制度和犯罪中规定情绪犯罪的责任。我国刑法可采取总括式立法对情绪加以评价。     

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.     

Ninhydrin Thiohemiketals: Basic Research Towards Improved Fingermark Detection Techniques Employing Nano‐Technology*

Abstract: In the first part of a comprehensive research project towards more efficient application of nano‐technology to fingerprint visualization, we investigated the possibility of more selective binding of gold nanoparticles (NP) to fingerprint material. We synthesized derivatives of ninhydrin and 1,2‐indanedione containing loosely bound thiol groups. In particular: thiohemiketals (THK) of ninhydrin, and thioketals of 1,2‐indanedione were prepared and tested as potential fingerprint reagents. By reacting ninhydrin with various thiols we were able to produce a series of novel THK, bearing the SR group always at C2. Ninhydrin THK reacted with amino acids to produce the expected Ruhemann’s purple, and they also developed latent fingermarks on paper in a similar manner to ninhydrin. Ketals and thioketals derived from 1,2‐indanedione reacted neither with amino acids nor with latent fingermarks. In the second part of the research, the thiols which are formed on the ridges as byproducts of the reaction with amino acids will be tested for their potential as stabilizers for gold NP that will become covalently bound to the fingerprint ridges.     

Automated Mapping of Explosives Particles in Composition C‐4 Fingerprints*†‡

Abstract: A method is described to perform automated mapping of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) particles in C‐4 fingerprints. The method employs polarized light microscopy and image analysis to map the entire fingerprint and the distribution of RDX particles. This method can be used to evaluate a large number of fingerprints to aid in the development of threat libraries that can be used to determine performance requirements of explosive trace detectors. A series of 50 C‐4 fingerprints were characterized, and results show that the number of particles varies significantly from print to print, and within a print. The particle size distributions can be used to estimate the mass of RDX in the fingerprint. These estimates were found to be within ±26% relative of the results obtained from dissolution gas chromatography/μ‐electron capture detection for four of six prints, which is quite encouraging for a particle counting approach. By evaluating the average mass and frequency of particles with respect to size for this series of fingerprints, we conclude that particles 10–20 μm in diameter could be targeted to improve detection of traces of C‐4 explosives.     

A Simple Computer‐assisted Quantification of Contrast in a Fingerprint

A simple method for quantification of contrast in a fingerprint is proposed. Contrast is defined as the average difference in intensity of pixels between valleys and ridges in a fingerprint. It is quantified from a scanner‐acquired image of the fingerprint using a histogram function of Adobe Photoshop. The method was validated with black inked prints and marks developed with aluminum powder. Moreover, we tested resistance of the method to rater‐dependent errors and dependence of the measurements on the resolution of an image and the model of the scanner. For both groups of fingerprints, the method gave coherent and easily interpretable quantitative values for contrast. There were no significant differences between measurements performed by different raters and by the same rater in a test–retest procedure. However, the method was found to be instrument dependent, as measurements were significantly affected by image resolution and the model of the scanner.     

Pore Sub‐Features Reproducibility in Direct Microscopic and Livescan Images—Their Reliability in Personal Identification

Abstract: Third level features have been reported to have equal discriminatory power as second level details in establishing personal identification. Pore area, as an extended set third level sub‐feature, has been studied by minimizing possible factors that could affect pore size. The reproducibility of pore surface area has been studied using direct microscopic and 500 ppi Livescan images. Direct microscopic pore area measurements indicated that the day on which the pore area was measured had a significant impact on the measured pore area. Pore area measurement was shown to be difficult to estimate in 500 ppi Livescan measurements owing to lack of resolution. It is not possible to reliably use pore area as an identifying feature in fingerprint examination.     

Carbon‐Based Fingerprint Powder as a One‐Step Development and Matrix Application for High‐Resolution Mass Spectrometry Imaging of Latent Fingerprints

Carbon‐based materials are often used as matrices for matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) and its imaging (MALDI‐MSI). However, researchers have refrained from using carbon‐based fingerprint powder (CFP) as a matrix due to high background and contamination. In this work, the compatibility of CFP is reevaluated with MALDI‐MSI using a high‐resolution mass spectrometer (HRMS) and compared to traditional organic matrices. Relevant fingerprint compounds were easily distinguished from carbon cluster peaks when using HRMS. For fair comparison, half of a fingerprint was dusted with CFP while the other half was dusted with traditional organic matrices. All compounds studied had comparable, or higher, signal‐to‐noise (S/N) ratios when CFP was used as the matrix. Additionally, chemical image qualities closely followed the trend of S/N ratios. CFP proved to be an effective one‐step development and matrix application technique for MALDI‐MSI of latent fingerprints, when carbon cluster peaks are well separated by a HRMS.     

指印检验新方面

100多年来指印鉴定一直是犯罪侦查最有效的个体识别手段,在物证鉴定领域占据重要地位,上世纪80~90年代指印检验技术研究的重要进步更是使指印物证技术应用达到一个新的水平。最近几年指印技术研究又取得许多新进展和突破,特别是在指印显现技术和指印纹线物质成分分析方面开创了新方法和新方向,形成指印物证应用新体系,但同时在指印鉴定结论可靠性方面也出现新争议。     

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.     

A Modified Electrostatic Adsorption Apparatus for Latent Fingerprint Development on Unfired Cartridge Cases

Visualization of latent fingerprints on metallic surfaces by the method of applying electrostatic charging and adsorption is considered as a promising chemical‐free method, which has the merit of nondestruction, and is considered to be effective for some difficult situations such as aged fingerprint deposits or those exposed to environmental extremes. In fact, a portable electrostatic generator can be easily accessible in a local forensic technology laboratory, which is already widely used in the visualization of footwear impressions. In this study, a modified version of this electrostatic apparatus is proposed for latent fingerprint development and has shown great potential in visualizing fingerprints on metallic surfaces such as cartridge cases. Results indicate that this experimental arrangement can successfully develop aged latent fingerprints on metal surfaces, and we demonstrate its effectiveness compared with existing conventional fingerprint recovery methods.     

Under the microscope: legal challenges to fingerprints and DNA as methods of forensic identification1

Suspects in legal cases can be identified by an ever‐growing list of novel methods. The most common techniques currently used include latent print and DNA analysis. Although standard fingerprinting entered the courtroom over a century ago, the admissibility of fingerprint evidence has undergone a period of intense scrutiny in the USA in recent years. In contrast, most challenges to DNA analysis as a science came during its inception in the late 1980s and early 1990s. Current challenges to fingerprint evidence attempt to discredit the science behind the theory whereas challenges to DNA evidence often bring into question the competency of the analyst. In either case, the lessons learned in various court systems give guidance for those implementing the newer emerging biometric identification technologies such as facial recognition systems, retinal scans and the like. The first section of this article deals with fingerprint analysis and recent challenges to fingerprint admissibility in US courts. The second section discusses the evolution of DNA analysis and relevant cases. The final section gives recommendations for emerging biometric technologies to follow to satisfy the standards set forth by the courts.     

Job satisfaction: validating Dantzker’s four-factor model using structural equation modeling

The purpose of this study was to examine the validity of the four-factor structure from a job satisfaction instrument. Dantzker’s job satisfaction instrument was designed to capture information on four factors: general administration, extras, job, and equipment. Using data from police officers that are middle management (n?=?136), we performed confirmatory factor analysis via structural equation modeling to validate that the four factors are actually capturing job satisfaction. The results of the study show that the four-factor solution fit the model satisfactorily. All of the factor loadings were large expect for one. The results suggest that the four-factor solution has proper validity to use with middle manager police officers. Post hoc simulation analyses (n?=?1000 replications) show that no bias in the factor loadings or standard errors was present in this analysis, and the study had sufficient statistical power.     

Mechanisms and Consequences of Professional Marginality: The Case of Poverty Lawyers Revisited

A partial replication of Jack Katz's (1982 ) Poor People's Lawyers in Transition, this article explores the manifestations and consequences of professional marginality of legal aid lawyers. Based on thirty‐five interviews with poverty attorneys and interns in Chicago, the authors show that scarce material resources and unclear expectations continue to give rise to the marginalization of this segment of the legal profession. The authors analyzed ideological, task, status, and material dimensions of attorneys' professional marginality. With no access to reform litigation, central to the legal aid “culture of significance” in the 1970s, present‐day poverty lawyers seek new ways to cope with marginality. The authors argue that these lawyers' coping strategies have many negative consequences. Thus, over time, poverty lawyers' deep engagement with clients, ideals of empowerment, and social justice orientation give way to emotional detachment, complacency, and an emphasis on “making do” within the constraints of the system.     

Surface Modification for the Collection and Identification of Fingerprints and Colorimetric Detection of Urea Nitrate

Glass surfaces were modified with a combination of dyes and reagents to allow for the potential simultaneous recording of a detailed fingerprint and the detection of the explosive urea nitrate (UN), as a proof of principle of surface modification for simultaneous linking of identity to manipulation of explosives. By coating microscope slides with 9,10‐diphenylanthracene (DPA), p‐dimethylaminobenzaldehyde (p‐DMAB) and p‐dimethylaminocinnamaldehyde (p‐DMAC), a colorimetric change was observed in the presence of UN, while revealing a fingerprint with enough resolution to isolate at least 10 minutiae. This is the first step in creating point‐of‐care devices capable of detecting low concentrations of explosives and drug metabolites and connecting them to a fingerprint.