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.     

Intellectual Quotient of Juveniles Evaluated in a Forensic Psychiatry Clinic After Committing a Violent Crime*

Abstract: The purpose of this preliminary study is to evaluate if there is a difference between the intelligence quotient (IQ) of 27 adolescent defendants referred to the Bellevue Hospital Center Forensic Psychiatry Clinic after committing violent crimes, and those adolescents in the same age group in the general population of the United States, as defined by the norms of the psychometric testing instrument Wechsler Intelligence Scale for Children, 4th edition (WISC‐IV). The IQ scores and sub‐scores were compared to IQ scores of the general population (mean = 100, SD = 15) using a Z‐test. The mean for the Full Scale IQ was 82.93. The means for the subtests which include Processing Speed Index, Perceptual Reasoning Index, Verbal Comprehension Index, and Working Memory Index, were: 78.48, 87.78, 86.70 (p < 0.05), and 90.78 (p = 0.09) respectively. There is a statistically significant difference in the IQ scores of the violent juveniles studied when compared to the general population.     

Stress and Deception in Speech: Evaluating Layered Voice Analysis*

Abstract: This study was designed to evaluate commonly used voice stress analyzers—in this case the layered voice analysis (LVA) system. The research protocol involved the use of a speech database containing materials recorded while highly controlled deception and stress levels were systematically varied. Subjects were 24 each males/females (age range 18–63 years) drawn from a diverse population. All held strong views about some issue; they were required to make intense contradictory statements while believing that they would be heard/seen by peers. The LVA system was then evaluated by means of a double blind study using two types of examiners: a pair of scientists trained and certified by the manufacturer in the proper use of the system and two highly experienced LVA instructors provided by this same firm. The results showed that the “true positive” (or hit) rates for all examiners averaged near chance (42–56%) for all conditions, types of materials (e.g., stress vs. unstressed, truth vs. deception), and examiners (scientists vs. manufacturers). Most importantly, the false positive rate was very high, ranging from 40% to 65%. Sensitivity statistics confirmed that the LVA system operated at about chance levels in the detection of truth, deception, and the presence of high and low vocal stress states.     

If Brain Scans Really Detected Deception,Who Would Volunteer to be Scanned?

Abstract: Recent neuroimaging studies investigating the neural correlates of deception among healthy people, have raised the possibility that such methods may eventually be applied during legal proceedings. Were this so, who would volunteer to be scanned? We report a “natural experiment” casting some light upon this question. Following broadcast of a television series describing our team’s investigative neuroimaging of deception in 2007, we received unsolicited (public) correspondence for 12 months. Using a customized template to examine this material, three independent assessors unanimously rated 30 of an initial 56 communications as unequivocally constituting requests for a “scan” (to demonstrate their author’s “innocence”). Compared with the rest, these index communications were more likely to originate from incarcerated males, who were also more likely to engage in further correspondence. Hence, in conclusion, if neuroimaging were to become an acceptable means of demonstrating innocence then incarcerated males may well constitute those volunteering for such investigation.     

Using Named Entities for Computer‐Automated Verbal Deception Detection

There is an increasing demand for automated verbal deception detection systems. We propose named entity recognition (NER; i.e., the automatic identification and extraction of information from text) to model three established theoretical principles: (i) truth tellers provide accounts that are richer in detail, (ii) contain more contextual references (specific persons, locations, and times), and (iii) deceivers tend to withhold potentially checkable information. We test whether NER captures these theoretical concepts and can automatically identify truthful versus deceptive hotel reviews. We extracted the proportion of named entities with two NER tools (spaCy and Stanford's NER) and compared the discriminative ability to a lexicon word count approach (LIWC) and a measure of sentence specificity (speciteller). Named entities discriminated truthful from deceptive hotel reviews above chance level, and outperformed the lexicon approach and sentence specificity. This investigation suggests that named entities may be a useful addition to existing automated verbal deception detection approaches.     

Effectiveness of deception detection training: a meta-analysis

Abstract

A meta-analysis was conducted to determine the overall effectiveness of deception detection training and to identify conditions that may moderate training effectiveness. The analysis was based on a total of 16 studies with 30 separate hypothesis tests, representing the behavior of 2847 trainees. Results indicated that the effect of deception detection training on detection accuracy was positive, significant, and of medium magnitude. Moreover, training effectiveness was moderated by the type of training implemented, training content, trainee expertise, and the type of lie told. Discussion centers on implications for training design and implementation.     

The Effects of Substance Use on Offender Crime Scene Behavior

Abstract:  Substance use has an effect on an individual's propensity to commit acquisitive crime with recent studies showing substance users more likely to leave forensic material at a crime scene. An examination of acquisitive crime solved in Northamptonshire, U.K., during 2006 enabled 70 crime scene behavior characteristics to be analyzed for substance and nonsubstance use offenders. Logistical regression analyses have identified statistically significant crime scene behavior predictors that were found to be either present at or absent from the crime scene when the offender was a substance user. Most significant predictors present were indicative of a lack of preparation by the offender, irrational behavior, and a desire to steal high value, easily disposed of, property. Most significant predictors absent from the crime scene were indicative of more planning, preparation, and execution by the offender. Consideration is given to how this crime scene behavior might be used by police investigators to identify offenders.     

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.     

A Fatal Shot with a Signal Flare—A Crime Reconstruction*

Abstract: A reconstruction of an incident of a fatal wounding of a football fan with a parachute flare was performed. Physical and chemical examinations of the victim’s trousers and parts of a flare removed from the wound in his leg were performed by means of an optical microscope and a scanning electron microscope coupled with an energy dispersive X‐ray spectrometer. Signs of burning were seen on the front upper part of the trousers, including a 35–40 mm circular hole with melted and charred edges. Postblast residue present on the surface of the trousers contained strontium, magnesium, potassium, and chlorine. Also the case files—the medical reports and the witnesses’ testimonies—were thoroughly studied. It has been found that the evidence collected in the case supported the version of the victim being shot by another person from a distance.     

Extracting Concealed Information from Groups*

Abstract: Lie detection procedures are typically aimed at determining guilt or innocence of a single suspect. Serious security threats, however, often involve groups, such as terrorist networks or criminal organizations. In this report, we describe a variant of the skin conductance‐based Concealed Information Test (CIT) that allows for the extraction of critical information from such groups. Twelve participants were given information about an upcoming (mock) terrorist attack, with specific instructions not to reveal this information to anyone. Next, each subject was subjected to a CIT, with questions pertaining to the details of the attack. Results showed that for every question, the average skin conductance response to the correct answer option differed significantly (p < 0.05) from those to all other options. These results show that the information about the upcoming attack could be extracted from the group of terror suspects as a whole.     

The Relationship Between Mental Disorders and Types of Crime in Inmates in a Brazilian Prison

This cross‐sectional study conducted in prisons in the city of Salvador, Bahia, Brazil, investigated the association between the presence of psychiatric disorders in 462 prisoners and the types of crimes committed by them. Psychiatric diagnosis was obtained by means of the Brazilian Portuguese version of the Mini‐International Neuropsychiatric Interview. A statistically significant association was found between some psychiatric disorders and specific groups of crime: lifelong substance addiction with sex crimes and homicide; antisocial personality disorder with robbery and with kidnapping and extortion; borderline personality disorder with sex crimes; and lifelong alcohol addiction with fraud and conspiracy and with armed robbery and murder. It was concluded that the mental disorders considered more severe (psychosis and bipolar disorder) were not associated with violent crimes, suggesting that the severity of the psychotic disorder may be the factor that has caused psychosis to be associated with violent crimes in previous studies.     

The Role of Forensic Botany in Crime Scene Investigation: Case Report and Review of Literature

Management of a crime is the process of ensuring accurate and effective collection and preservation of physical evidence. Forensic botany can provide significant supporting evidences during criminal investigations. The aim of this study is to demonstrate the importance of forensic botany in the crime scene. We reported a case of a woman affected by dementia who had disappeared from nursing care and was found dead near the banks of a river that flowed under a railroad. Two possible ways of access to crime scene were identified and denominated “Path A” and “Path B.” Both types of soil and plants were identified. Botanical survey was performed. Some samples of Xanthium Orientalis subsp. Italicum were identified. The fall of woman resulted in external injuries and vertebral fracture at autopsy. The botanical evidence is important when crime scene and autopsy findings are not sufficient to define the dynamics and the modality of death.     

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.     

The Value of Crime Scene and Site Visitation by Forensic Psychologists and Psychiatrists

Site visits and crime scene visitation by forensic psychologists and psychiatrists may enhance the accuracy and credibility of their forensic work in criminal, civil, and other important contexts. This ethically sound technique of after‐the‐fact data collection and verification offers numerous potential benefits to the forensic mental health professional: clarifying the subject's actions, assessing the reliability of witness reports, identifying contextual determinants of behavior, and more fully illuminating subject motivation and decision‐making. Limitations and suggested guidelines for conducting site visits are offered. Guidelines include preplanning, arranging for an informed guide to accompany and narrate the visit, and conducting the site visit prior to forensic examinations.     

犯罪现场生物检材的发现、提取策略

在改进现场生物检材的发现和提取技术的同时,也要进行理论创新和体系构建,才能够更好地指导实践。全局的观点、具体案件具体分析和犯罪现场重建对于现场勘查中有效地发现、提取和利用生物检材是十分重要的。     

Prediction of Projectile Ricochet Behavior After Water Impact*

Abstract: Although not very common, forensic investigation related to projectile ricochet on water can be required when undesirable collateral damage occurs. Predicting the ricochet behavior of a projectile is challenging owing to numerous parameters involved: impact velocity, incident angle, projectile stability, angular velocity, etc. Ricochet characteristics of different projectiles (K50 BMG, 0.5‐cal Ball M2, 0.5‐cal AP‐T C44, 7.62‐mm Ball C21, and 5.56‐mm Ball C77) were studied in a pool. The results are presented to assess projectile velocity after ricochet, ricochet angle, and projectile azimuth angle based on impact velocity or incident angle for each projectile type. The azimuth ranges show the highest variability at low postricochet velocity. The critical ricochet angles were ranging from 15 to 30°. The average ricochet angles for all projectiles were pretty close for all projectiles at 2.5 and 10° incident angles for the range of velocities studied.     

Detection and Classification of Ignitable Liquid Residues Using a Fluorescence‐Based Vapor‐Sensitive Microsphere Array*

Abstract: This paper describes the application of microsphere vapor sensing arrays to the detection of ignitable liquid (IL) vapors as both pure vapors and as residues (ILRs) on simulated fire debris samples. The temporal fluorescence response profile of the microsphere array generated a reproducible pattern unique to each analyte that could be used to classify subsequent sensor responses. This system, together with a support vector machine pattern recognition algorithm, was used to address several different IL and ILR classification scenarios. High classification accuracy (98%) was maintained over more than 200 vapor responses and the array was able to identify ILs when presented to the pattern classification algorithm within a dataset containing 11 other volatile compounds. Both burned and unburned IL treated samples were classified correctly greater than 97% of the time. These results indicate that microsphere vapor sensing arrays may be useful for the rapid identification of ILs and ILRs.     

Unusual Death of a Transvestite: Identification of Crime Weapon and Survival Time*

Abstract: The authors report a case of a transvestite found murdered near his automobile with several lacerated contused wounds to the face and cranial fractures. Autopsy revealed that the cause of death was a serious head trauma with subdural and subarachnoidal hemorrhages. In order to identify the crime weapon, a scanning electron microscopy (SEM) was used which revealed metallic residue on the skin fragments with the same molecular composition of the car paint. As for survival time, antibody anti‐beta‐amyloid precursor protein (APP) was applied to brain fragments and brainstem tissue, allowing for axonal varicosities (which form 2 to 3 h following death) to be observed under the optic microscope. So, by using SEM we understood that the fatal cranial‐encephalic lesions were the result of the victim’s head being repeatedly struck against the car door while anti‐betaAPP led to the understanding that the time elapsed between injury and death was less than 2 to 3 h.     

The Influence of New Technologies on the Visual Attention of CSIs Performing a Crime Scene Investigation

Currently, a series of promising new tools are under development that will enable crime scene investigators (CSIs) to analyze traces in situ during the crime scene investigation or enable them to detect blood and provide information on the age of blood. An experiment is conducted with thirty CSIs investigating a violent robbery at a mock crime scene to study the influence of such technologies on the perception and interpretation of traces during the first phase of the investigation. Results show that in their search for traces, CSIs are not directed by the availability of technologies, which is a reassuring finding. Qualitative findings suggest that CSIs are generally more focused on analyzing perpetrator traces than on reconstructing the event. A focus on perpetrator traces might become a risk when other crime‐related traces are overlooked, and when analyzed traces are in fact not crime‐related and in consequence lead to the identification of innocent suspects.     

Infrared Imaging of the Crime Scene: Possibilities and Pitfalls

All objects radiate infrared energy invisible to the human eye, which can be imaged by infrared cameras, visualizing differences in temperature and/or emissivity of objects. Infrared imaging is an emerging technique for forensic investigators. The rapid, nondestructive, and noncontact features of infrared imaging indicate its suitability for many forensic applications, ranging from the estimation of time of death to the detection of blood stains on dark backgrounds. This paper provides an overview of the principles and instrumentation involved in infrared imaging. Difficulties concerning the image interpretation due to different radiation sources and different emissivity values within a scene are addressed. Finally, reported forensic applications are reviewed and supported by practical illustrations. When introduced in forensic casework, infrared imaging can help investigators to detect, to visualize, and to identify useful evidence nondestructively.