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.     

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.     

An Approach to Speaker Identification

This presentation will provide standards upon which any attempts to meet the challenge of identifying speakers by voice should be based. It is organized into a model based on (i) application of a rigorous research program validating the system, (ii) an upgrading of the organization of the SI area, and (iii) exploitation of new technology. The second part of the presentation will describe an illustrative speech/voice approach to SI development. This effort is also based on an extensive corpus of research. It is suggested that application of the cited standards, plus the illustrative model, will permit reasonable progress to be made. Finally, a number of procedural recommendations are made; they should enhance the efficacy of the proposed approach.     

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.     

Empirical Limits for the Forensic Assessment of PTSD Litigants

This paper discusses the limits of expert opinion on posttraumatic stress disorder (PTSD) in personal injury claims. The construct of PTSD is hampered by several empirical limitations. Multiple reliable measures of PTSD exist, but have not been evaluated sufficiently within litigating samples and are infrequently used by forensic assessors. Common methods for trauma screening appear insensitive. Opinions about causation of PTSD and disability are complicated by retrospective memory biases, as well as the failure of most anxiety disorders to be detected within primary medical care. PTSD appears to have a steep spontaneous remission curve during the first year, but at least 10% of trauma-exposed people suffer chronic distress. Little is known about the course beyond 1 year. Efficacious psychological treatments have been developed for PTSD, but are not in common use limiting claimants access to rehabilitative treatments. Research on functional disability associated with PTSD is in its infancy, but it seems likely that PTSD will account for only a part of the variance in work disability. We provide suggestions for improving forensic practice, advising the courts about the limitations of forensic opinions, and necessary research.     

Evaluation of Purkait's triangle method for determining sexual dimorphism

The identification of sex from the skeleton is an important demographic assessment in medicolegal investigations. Rama Purkait developed a method for estimating sex using measurements from a triangle defined by three points on the proximal end of the femur using skeletal material from Bhopal, India. This method was tested with measurements on 200 Indo-European and African American adult femora from the Terry collection using discriminant function analysis to determine if Purkait's method was valuable for determining sex in Americans. A side-by-side analysis was conducted of Purkait's "triangle method" and the maximum diameter of the femoral head to determine their relative value in assessing sexual dimorphism. In the study sample a single variable from Purkait's method provided 85.5% prediction accuracy, similar to 87% for the head diameter. Combining threshold values for a single variable from Purkait's method and the femoral head diameter raised the predictability to greater than 90% for both sexes.     

辨证认识话者自动识别系统

为了警示近年来我国司法话者识别领域中出现的一些崇外、盲目追求快速与省事的苗头,结合话者自动识别系统的研究、应用状况,从语音的共性与个性、话者识别结果的相对性与绝对性出发,通过分析比对话者自动识别与语音识别所用的特征参数及实现过程,辨证分析了制约话者自动识别系统准确率的根本原因。指出了话者自动识别系统尚无法达到人们对其的期望,以及适合于司法诉讼领域的话者自动识别系统的发展方向。     

Evaluation of the Suchey-Brooks method for aging skeletons in the Balkans

This study has been carried out to examine whether the Suchey-Brooks (S&B) methods could be successfully applied in age assessment of populations from the Balkans. The known-age sample consists of 33 females and 52 males pairs of pubic bones collected from the autopsy cases. Age estimation by S&B method showed an accuracy of 89.74% in males and 72.0% in females. Statistical analysis showed a positive correlation between the actual age of the investigated individuals and age phases obtained by the S&B method, although the mean values of the sixth age category differed significantly compared with the original model. The most reliable indicators in both sexes were the relief of the symphyseal surface, lipping, symphyseal rim, and dorsal margin. The discriminating power of these indicators was the least reliable in distinguishing S&B phases 2 and 3. Based on these results, the appropriate recommendations for aging Serbian populations are made. There was a good agreement between two observers (kappa=0.726).     

Evaluation of Stature Estimation from the Database for Forensic Anthropology*†

Abstract: Trotter and Gleser’s ( 1 - 3 ) stature equations, conventionally used to estimate stature, are not appropriate to use in the modern forensic context. In this study, stature is assessed with a modern (birth years after 1944) American sample (N = 242) derived from the National Institute of Justice Database for Forensic Anthropology in the United States and the Forensic Anthropology Databank. New stature formulae have been calculated using forensic stature (FSTAT) and a combined dataset of forensic, cadaver, and measured statures referred to as Any Stature (ASTAT). The new FSTAT‐based equations had an improved accuracy in Blacks with little improvement over Ousley’s ( 4 ) equations for Whites. ASTAT‐based equations performed equal to those of FSTAT equations and may be more appropriate, because they reflect both the variation in reported statures and in cadaver statures. It is essential to use not only equations based on forensic statures, but also equations based on modern samples.     

Evaluation of Computed Tomography as a Screening Test for Death Inquest

Abstract: The Japanese method of inquest, which depends mostly on external examinations, may misdiagnose a considerable number of accidental deaths and suicides as death by disease. We conducted computed tomography (CT) scans of 80 cases for which police concluded death by disease or natural causes based on police investigations into the circumstances and results from external examinations. The cause of death was clearly determined by CT scan in 17 of 80 cases. Ten cases underwent autopsy after the police suspected criminality based on results of the CT examinations. The results suggest CT scan may be a tool for preventing a number of overlooked crimes and accidents in Japan. However, it cannot be a perfect tool for discerning between death by disease and other causes of death without cooperation from the investigative agencies and subsequent forensic examinations such as autopsy and toxicological tests.     

Psychological autopsy in the investigation of serial neonaticides

While the use of psychological autopsies has at least a 50-year history in the investigation of equivocal deaths and suicides, we report a case where, after the discovery of a woman who died of natural causes, a subsequent search of her home found three deceased newborn infants. The infants were born on three separate occasions; the most recent was delivered approximately 2 weeks before the death of the mother. Using her own diaries and interviews with family and friends along with the physical autopsy and scene investigation data, we built a psychological autopsy that addressed the mother's mental state over the period of time when the infants' deaths took place. While the use of the psychological autopsy was not employed to distinguish the manner of death of the mother, it did provide explanatory power over circumstances of the crime scene and the behavioral disturbance of the mother.     

Tables for the Metric Evaluation of Pair‐Matching of Human Skeletal Elements

A common task in forensic anthropology involves pair‐matching of left and right skeletal elements. This can be achieved through visual pair‐matching by evaluating similarities in morphology, and through osteometric sorting, a quantitative technique. To simplify the process of osteometric sorting, this article explains the use of a statistic (M), which captures the amount of size variation found between homologous bones from single individuals. A database of skeletal measurements for all major paired postcranial bones is used to calculate values of M from a variety of sources. The maximum value and the 90th and 95th percentiles of M are provided in tabular format, and values of M from forensic cases can be compared to these tables as an objective means for determining whether homologous bones could have originated from the same individual. This simple technique can be combined with visual pair‐matching to be particularly effective in cases involving commingling of skeletons.     

Effect of two types of control questions and two question formats on the outcomes of polygraph examinations

Abstract: Two major variations of polygraph “Control Question” testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or “time bar” (e.g., “Before you were 21, did you ever...”) and Nonexclusive or “no time bar”(e.g., “Did you ever….?”) was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject’s sex. Accuracy was significantly related to the type of control question [χ²(2) = 11.46, p = 0.003; τc = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects’ self‐reports support the general “theory” on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings.     

A Forensic and Medical Evaluation of Dog Bites in a Province of Western Turkey

The aim was to evaluate the demographic data of dog‐bite cases organized from criminal and forensic reports. This study evaluated 328 cases admitted to the Director of Forensic Medicine, Eskisehir, as a result of dog bites between January 1, 2006 and December 31, 2010. It was found that those in the age‐group of 0–18 were most frequently exposed to dog bites (48.5%). Injuries to the lower extremity, upper extremity, and chest/abdomen/back were more frequent in men (72.6%, 76.4%, and 66.1%, respectively), while injuries to the head/neck/face were more frequent in women (52.3%) (p < 0.01). While most of those wounded in the upper extremity, the head/neck/face, and the chest/abdomen/back were in the child age‐group, most of those wounded in the lower extremity were in the adult age‐group (p < 0.001). Teaching children, in particular, how to behave around dogs would be useful in reducing the incidence of bite.     

Evolution of the Psychological Autopsy: Fifty Years of Experience at the Los Angeles County Chief Medical Examiner‐Coroner's Office

The origin of the psychological autopsy was in the late 1950s and the result of a collaboration between the Los Angeles County Chief Medical Examiner‐Coroner's Office and the Los Angeles Suicide Prevention Center. It was conceptualized as a thorough retrospective analysis of the decedent's state of mind and intention at the time of death. It was used initially in “equivocal” deaths where the manner of death was possibly either suicide or accident. Later, it was used in cases where a party (primarily family members) protested the Medical Examiner‐Coroner's suicide determination. Over the past 25 years, the University of Southern California Institute of Psychiatry, Law, and Behavioral Science has served as the psychiatric/psychological consultants to the Coroner's Department. Research findings, the use of this approach in high‐profile cases, and the most recent manner in which the psychological autopsy is conducted are discussed.     

Psychological adjustment in a forensic sample: relationship with approach- and avoidance-coping typologies

Most studies that relate coping strategies with psychological symptoms usually consider a single coping dimension. This means that interpretation of the results is unclear and only partially true as subjects activate different types of coping strategies simultaneously when faced with a stressor. The objective of the present study is to analyze the relationships between coping and psychopathology in young inmates, taking into account the number of approach and avoidance answers simultaneously. The results show that the inmates with above-average scores in avoidance coping and below average in those of approach (coping responses inventory--adult form, [CRI-A]) show higher symptomatology (MMPI-2) than the inmates who obtain above-average scores in both avoidance and approach strategies. It can be deduced that it is not the high use of avoidance coping that is related to psychopathology, but rather the combined use of many avoidance strategies and few approach strategies. The convenience of jointly taking into account both types of coping is discussed.     

鉴定人的责任负担

鉴定人是司法鉴定活动的决定性因素。鼓励专家参与法庭服务与约束专家独立、客观实施鉴定这一对矛盾需要通过制度的合理设置达到一定的平衡状态,以适合诉讼活动的开展。鉴定人的责任负担是体现对鉴定人实施鉴定活动进行约束的主要手段,也是我国进一步深化司法鉴定体制改革不可回避的重要内容之一。