ID‐Check: Online Concealed Information Test Reveals True Identity

The Internet has already changed people's lives considerably and is likely to drastically change forensic research. We developed a web‐based test to reveal concealed autobiographical information. Initial studies identified a number of conditions that affect diagnostic efficiency. By combining these moderators, this study investigated the full potential of the online ID‐check. Participants (n = 101) tried to hide their identity and claimed a false identity in a reaction time‐based Concealed Information Test. Half of the participants were presented with personal details (e.g., first name, last name, birthday), whereas the others only saw irrelevant details. Results showed that participants′ true identity could be detected with high accuracy (AUC = 0.98; overall accuracy: 86–94%). Online memory detection can reliably and validly detect whether someone is hiding their true identity. This suggests that online memory detection might become a valuable tool for forensic applications.     

The Concealed Information Test is Susceptible to Misleading Information

An approach toward detecting hidden knowledge is the Concealed Information Test (CIT). It relies on the memory of crime‐relevant information. This study investigated whether its validity is susceptible to memory distortion by misleading information. A misleading information paradigm was employed to distort memory prior to an interrogation with a CIT. Forty‐one participants watched a video with specific crime‐related information. After a 1‐week retention interval, misleading information was introduced. Afterward, a CIT was performed, followed by a threefold memory test. When misleading information was presented, memory performance was reduced, and no physiological response differences between crime‐relevant and crime‐irrelevant information were found. Without presenting misleading information, physiological responses differed between responses to crime‐relevant and crime‐irrelevant information. However, responses in all physiological measures also differed between misleading and irrelevant information. The results indicate that the CIT is susceptible to misleading information, which reduces its validity in specific constellations.     

Psychophysiological Responses of People with Psychopathic Tendencies to the Concealed Information Test

This study was designed to investigate differences in psychophysiological responses among individuals with psychopathic tendencies. A total 40 students were participated and were divided into two groups based on Levenson Self‐Report Psychopathy Scale (LSRP) scores: a high psychopathic tendency group selected from the top 5% of LSRP scores, and a low psychopathic tendency group selected from the bottom 5% of LSRP scores. All participants were instructed to perform a mock crime and complete the concealed information test (CIT). Results indicate that significant differences between crime‐relevant questions and irrelevant questions were observed for respiration line length and skin conductance response in both groups, but heart rate did not significantly differ between groups. There were no differences in psychophysiological responses between the groups. In conclusion, CIT was found to be an effective method for detecting crime‐relevant information in individuals with psychopathic tendencies.     

人隐瞒信息状态下多通道事件相关电位的研究

目的采用隐瞒信息测试(concealed informationtest,CIT)模式和多通道事件相关电位(event related potential,ERP)技术,对人类大脑在不同刺激下各脑区域活动情况和活跃程度进行对比,从神经电生理学层面揭示CIT模式隐瞒信息状态下视觉刺激人类大脑认知相关脑功能区特征。方法参考犯罪知情测试模式(GKT)的CIT模式,选用传统扑克牌,对17名被试人员进行视觉刺激,包括:靶、探测、无关和中立刺激,获得29通道ERP波。结果靶、探测和无关刺激平均按键反应时间:775ms、774ms和720ms;探测和无关刺激各通道P300峰潜伏期配对t检验,有统计学意义(P0.05)的通道有4个;探测和无关刺激各通道P300平均波幅(400~700ms)进行配对t检验,有统计学意义(P0.05)的通道有19个。结论隐瞒知晓信息是一个由多个脑功能皮质共同完成的复杂过程,与诚实反应抑制有密切关系,与额叶前部和上部皮质、前扣带回皮质(ACC)和缘上回等脑功能皮质特异相关。     

Functional MRI Detection of Deception After Committing a Mock Sabotage Crime*

Abstract: Using Blood Oxygen Level Dependent (BOLD) functional MRI (fMRI) to detect deception is feasible in simple laboratory paradigms. A mock sabotage scenario was used to test whether this technology would also be effective in a scenario closer to a real‐world situation. Healthy, nonmedicated adults were recruited from the community, screened, and randomized to either a Mock‐crime group or a No‐crime group. The Mock‐crime group damaged and stole compact discs (CDs), which contained incriminating video footage, while the No‐crime group did not perform a task. The Mock‐crime group also picked up an envelope from a researcher, while the No‐crime group did not perform this task. Both groups were instructed to report that they picked up an envelope, but did not sabotage any video evidence. Participants later went to the imaging center and were scanned while being asked questions regarding the mock crime. Participants also performed a simple laboratory based fMRI deception testing (Ring‐Watch testing). The Ring‐Watch testing consisted of “stealing” either a watch or a ring. The participants were instructed to report that they stole neither object. We correctly identified deception during the Ring‐Watch testing in 25 of 36 participants (Validated Group). In this Validated Group for whom a determination was made, computer‐based scoring correctly identified nine of nine Mock‐crime participants (100% sensitivity) and five of 15 No‐crime participants (33% specificity). BOLD fMRI presently can be used to detect deception concerning past events with high sensitivity, but low specificity.     

The Accuracy of Auditors' and Layered Voice Analysis (LVA) Operators' Judgments of Truth and Deception During Police Questioning*

The purpose of this study was to determine if auditors could identify truthful and deceptive persons in a sample (n = 74) of audio recordings used to assess the effectiveness of layered voice analysis (LVA). The LVA employs an automated algorithm to detect deception, but it was not effective here. There were 31 truthful and 43 deceptive persons in the sample and two LVA operators averaged 48% correct decisions on truth‐tellers and 25% on deceivers. Subsequent to the LVA analysis the recordings were audited by three interviewers, each independently rendering a decision of truthful or deceptive and indicating their confidence. Auditors' judgments averaged 68% correct decisions on truth‐tellers and 71% on deceivers. Auditors' detection rates, generally, exceeded chance and there was significantly (p < 0.05) greater confidence on correct than incorrect judgments of deceivers but not on truth‐tellers. These results suggest that the success reported for LVA analysis may be due to operator's judgment.     

Actions Speak Louder than Words: A Behavioral Analysis of 183 Individuals Convicted for Terrorist Offenses in the United States from 1995 to 2012

Involvement in terrorism has traditionally been discussed in relatively simplistic ways with little effort spent on developing a deeper understanding of what involvement actually entails, and how it differs from person to person. In this paper, we present the results of a three‐year project focused on 183 individuals associated with the global jihadist movement who were convicted in the United States, for terrorist offenses, between 1995 and 2012. These data were developed by a large‐scale, open‐source data collection activity that involved a coding dictionary of more than 120 variables. We identify and explore the diversity of behaviors that constitute involvement in terrorism. We also compare lone actors and those who acted as part of a group, finding that lone actors differed from group‐based actors in key demographic attributes and were more likely to be involved in attack execution behaviors. Implications for counterterrorism are then discussed.     

Assessment of Wear‐Related Features of the Kerf Wall from Saw Marks in Bone*†

Abstract: Analyses of saw marks in bone may yield important information about the class characteristics of saws used in postmortem dismemberments, yet little research has been directed at identifying saws’ individualizing characteristics. This study adds to existing saw mark analysis methodologies by examining wear‐related features of kerf walls using light‐ and environmental scanning electron microscopy. A crosscut saw and hacksaw were used to create sequences of 30 cuts in bone; these sequences reveal patterns of progressive loss of fine details of kerf wall morphology with increasing saw blade wear, because of the rounding of sharp points and edges. Nevertheless, diagnostic kerf wall features used to establish class characteristics persist despite these wear‐related changes. Unsuccessful attempts at statistical analysis of wear‐related changes, based on striae width and density, suggest these patterns are not readily quantifiable. Additionally, despite the scanning electron microscope’s superior imaging capabilities, it provided few practical, methodological gains over traditional light microscopy.     

A Bayesian Approach to Age Estimation in Modern Americans from the Clavicle*

Abstract: Clavicles from 1289 individuals from cohorts spanning the 20th century were scored with two scoring systems. Transition analysis and Bayesian statistics were used to obtain robust age ranges that are less sensitive to the effects of age mimicry and developmental outliers than age ranges obtained using a percentile approach. Observer error tests showed that a simple three‐phase scoring system proved the least subjective, while retaining accuracy levels. Additionally, significant sexual dimorphism was detected in the onset of fusion, with women commencing fusion at least a year earlier than men (women transition to fusion at approximately 15 years of age and men at 16 years). Significant secular trends were apparent in the onset of skeletal maturation, with modern Americans transitioning to fusion approximately 4 years earlier than early 20th century Americans and 3.5 years earlier than Korean War era Americans. These results underscore the importance of using modern standards to estimate age in modern individuals.     

Efficacy of Several Candidate Protein Biomarkers in the Differentiation of Vaginal from Buccal Epithelial Cells*

Abstract: Currently, there is no accurate method to differentiate vaginal epithelial cells from buccal epithelial cells in biological samples typically encountered in forensic casework. This study tested the expression of a selection of candidate proteins in buccal and vaginal epithelial cells. We investigated six candidate biomarkers, such as loricrin, vimentin, stratifin, cytokeratin 4, cytokeratin 13, small proline‐rich protein 2, and involucrin, using Western blot analysis on whole protein extracts and immunohistochemistry (IHC) on intact cells in an attempt to identify cell‐specific markers that would differentiate these cells by microscopy. Involucrin, loricrin, and stratifin showed differential expression during Western blot analysis and were carried through to IHC. Although proteins unique to vaginal epithelial cells and buccal epithelial cells were not identified from among the proteins tested, the increased expression levels of two proteins, loricrin and stratifin in vaginal cells, when compared to buccal cells, do provide encouraging results in the search for epithelial cell‐specific markers.     

The Recovery of Latent Fingermarks from Evidence Exposed to Ionizing Radiation*

Abstract: Continual reports of illicit trafficking incidents involving radioactive materials have prompted authorities to consider the likelihood of forensic evidence being exposed to radiation. In this study, we investigated the ability to recover latent fingermark evidence from a variety of substrates that were exposed to ionizing radiation. Fingermarks deposited on common surfaces, including aluminum, glass, office paper, and plastic, were exposed to doses ranging from 1 to 1000 kGy, in an effort to simulate realistic situations where evidence is exposed to significant doses of radiation from sources used in a criminal act. The fingermarks were processed using routine fingermark detection techniques. With the exception of glass and aluminum substrates, radiolysis had a considerable effect on the quality of the developed fingermarks. The damage to ridge characteristics can, in part, be attributed to chemical interactions between the substrate and the components of the fingermark secretions that react with the detection reagents.     

Recovery efficiencies of anthrax spores and ricin from nonporous or nonabsorbent and porous or absorbent surfaces by a variety of sampling methods*

The 2001 anthrax letter cases brought into focus the need to establish the most effective environmental sampling procedures. Results are presented from two studies aimed at establishing the best procedures for everyday surfaces likely to be contaminated after the release of environmentally stable bioaggressive agents, as exemplified by anthrax spores and ricin. With anthrax spores, contact plates, with mean retrieval rates of 28-54%, performed better than other methods by a wide margin for flat nonporous, nonabsorbent surfaces. They also proved best on flat porous, absorbent materials, although recoveries were low (<7%). For both agents, dry devices (swabs, wipes, Trace Evidence Collection Filters) had universally poor retrieval efficiencies with no significant differences between them. Among moistened devices (wipes, swabs, and Sample Collection and Recovery Devices), wipes were generally best, albeit with considerable cross-over among individual readings (highest mean recoveries for anthrax spores and ricin 5.5% and 2.5%, respectively, off plastic).     

Comparative Analysis of the Effects of Heat on the PCR‐Amplification of Various Sized DNA Fragments Extracted from Sus Scrofa Molars*

Abstract: This study examined the effects of heat on the amplification of DNA from the dental pulp of Sus scrofa molars and investigated the protection afforded to the pulp tissue by the dental enamel, alveolar process, and soft tissue of the head. Segments of defleshed maxilla and mandible encasing the first molar (n = 60) were subject to a range of temperatures for 15 min. Dental pulps were retrieved. Amplifications using three‐primer and four‐primer multiplexes showed no degradation of the largest fragment following exposure to 450°C. Amplifications in the three‐primer multiplex (283 bp) were successful following exposure to 525°C in maxillary samples only. This study revealed the enamel density of maxillary molars to be greater than mandibular molars in Sus scrofa. Following incineration of intact heads for 15 min (n = 10) and 1 h (n = 4) at an average temperature of 625°C, amplifications of the largest fragment (450 bp) were successful from both maxillary and mandibular teeth.     

Feasibility of Canine Detection of Mass Storage Devices: A Study of Volatile Organic Compounds Emanating from Electronic Devices Using Solid Phase Microextraction

Detection of canines are well‐known to be valuable in the location of contraband, such as explosives or narcotics. More recently, canines have been trained and utilized in the detection of concealed mass storage devices that might contain evidence of illegal activity such as child pornography. To lay the analytical foundation for this detection work, research was carried out to determine the volatile organic compounds associated with mass storage devices (MSD) that could be used by trained canines for detection. Headspace analysis of a variety of electronic devices was performed using solid phase microextraction (SPME) with gas chromatography/mass spectrometry (GC/MS). Analyses found several volatile compounds common to SIM and SD cards, as well as USB drives, including 2‐propenenitrile, styrene, isophorone, hydroxycyclohexyl phenyl ketone, and 2‐furanmethanol, tetrahydro. Results indicated that mass storage devices do have a characteristic odor profile making detection with minimal false alerts feasible for trained canines.     

Potency Trends of Δ9‐THC and Other Cannabinoids in Confiscated Cannabis Preparations from 1993 to 2008*

Abstract: The University of Mississippi has a contract with the National Institute on Drug Abuse (NIDA) to carry out a variety of research activities dealing with cannabis, including the Potency Monitoring (PM) program, which provides analytical potency data on cannabis preparations confiscated in the United States. This report provides data on 46,211 samples seized and analyzed by gas chromatography‐flame ionization detection (GC‐FID) during 1993–2008. The data showed an upward trend in the mean Δ⁹‐tetrahydrocannabinol (Δ⁹‐THC) content of all confiscated cannabis preparations, which increased from 3.4% in 1993 to 8.8% in 2008. Hashish potencies did not increase consistently during this period; however, the mean yearly potency varied from 2.5–9.2% (1993–2003) to 12.0–29.3% (2004–2008). Hash oil potencies also varied considerably during this period (16.8 ± 16.3%). The increase in cannabis preparation potency is mainly due to the increase in the potency of nondomestic versus domestic samples.