Lawyers' Questioning: The Effect of Confusing Questions on Witness Confidence and Accuracy

The present study investigated the effect on witness confidence and accuracy of confusing questions often used by attorneys in court. Participants viewed a videotaped film and were individually questioned about the incident 1 week later. Half the participants were asked questions using six categories of confusing questions (negatives, double negatives, leading, multiple questions, complex syntax, and complex vocabulary); the remaining half were asked for the same information using simply phrased equivalents. Confusing questions reduced participant-witnesses' accuracy and suppressed confidence–accuracy relationships compared with the condition where simplified alternatives were asked. Witness performance was impaired by the fact that mock-witnesses rarely asked for a confusing question to be explained or qualified their answers. This experiment demonstrates the importance of ensuring that lawyers ask witnesses simple, clear, questions.     

英语含蓄否定的界定、表现形式及其翻译

含蓄否定指形式肯定而意义否定或形式否定而意义肯定,是英语中一种常见的语言现象。科学地界定其范围有助于深入研究这一语言现象。归纳、分析英语中容易令人误入歧途的含蓄否定的表现形式,探讨它们在汉英翻译时应注意的问题,对提高跨文化交际能力具有很高的实用价值。     

The Direct and Cross-Examination of Complainants and Defendants in Rape Trials: A Quantitative Analysis of Question Type

This paper is a post-hoc examination of the questioning used in six rape trials. Questions asked in the evidence-in-chief and cross-examination of six complainants and five defendants were coded into different categories. The categories comprised "open", "closed", "leading", "heavily-leading" and "yes/no" questions; questions that are known to increasingly constrain witness responses. Additionally, the frequency of "multiple questions", and questions with "negatives" and "double negatives" were recorded; questions that witnesses have difficulty understanding. Broadly speaking, results showed that questions in both evidence-in-chief and cross-examination were of a constraining nature and allowed witnesses little opportunity to provide complete accounts of alleged events, particularly during cross-examination. Multiple questions were frequent although negatives were comparatively rare, and double negatives did not occur. Similar forms of questioning were used for complainants as for defendants, although more questions were asked of complainants than defendants in cross-examination. The results are discussed in terms of the adverse influence of these questioning strategies on the completeness and accuracy of witnesses' responses, and the similarity in "combativeness" of lawyers in their examination of complainants and defendants.     

Screening for drugs in forensic blood samples using EMIT urine assays

A screening method for the detection of drugs in haemolysed whole blood has been evaluated. Methanolic extracts of 300 forensic blood samples known to be positive or negative for drugs were analysed with EMIT d.a.u. assay kits for amphetamine, cannabinoids, opiates and benzodiazepines (the latter to analyse for diazepam and the main metabolite N-desmethyldiazepam). There were very few false positive results, except for the amphetamine assay in postmortem blood samples, where 9% were false positive. For amphetamine and cannabinoids a few false negatives were found, these were from samples with very low drug concentrations. No false negatives were found for opiates and diazepam. The present modification of the EMIT d.a.u. method seems to be a good method for screening of drugs in forensic blood samples, except for amphetamine in postmortem samples. The method is simple and requires only 0.5 ml blood.     

When lawyers question children

This study assessed the impact of some complex question forms frequently used by attorneys who examine and cross-examine witnesses in the courtroom. Fifteen males and 15 females from each of four student populations (kindergarten, fourth grade, ninth grade, and college) viewed a videotaped incident and then responded to questions about the incident. Half the questions were asked in “law-yerese” (i.e., using complex question forms); the remaining half asked for the same information using simply phrased question forms of the same length. Lawyerese confused children, adolescents, and young adults alike. Questions that included multiple parts with mutually exclusive responses were the most difficult to answer; those that included negatives, double negatives or difficult vocabulary also posed significant problems. Results suggest that complex question forms impede truth-seeking and should be prohibited in court.     

Evaluation of immunoassay methods for the screening of cocaine metabolites in urine

Immunoassay kits for urine cocaine (and metabolite) screening, obtained from two commercial sources, were examined for correlation of their results, expressed in terms of equivalent benzoylecgonine concentration, with the gas chromatography/mass spectrometry (GC/MS) concentration of benzoylecgonine. The correlation coefficients obtained, based on 62 (out of a total sample population of 3295) highly relevant samples, were 0.467 and 0.766 for Abuscreen (ARIA) and TDx (TDX), respectively. The preliminary screen cutoff values, which correspond to 150 ng/mL benzoylecgonine (as determined by GC/MS), were calculated based on the resulting regression equations and found to be 380 and 190 ng/mL for ARIA and TDX, respectively. With these cutoff values, ARIA generates 5 false negatives and 16 unconfirmed presumptive positives, while TDX results in 3 false negatives and 6 unconfirmed presumptive positives.     

Analytical Thresholds and Sensitivity: Establishing RFU Thresholds for Forensic DNA Analysis,

Determining appropriate analytical thresholds (ATs) for forensic DNA analysis is critical to maximize allele detection. In this study, six methods to determine ATs for forensic DNA purposes were examined and compared. Four of the methods rely on analysis of the baseline noise of a number of negatives, while two utilize the relationship between relative fluorescence unit signal and DNA input in the polymerase chain reaction (PCR) derived from a dilution series ranging from 1 to 0.06 ng. Results showed that when a substantial mass of DNA (i.e., >1 ng) was amplified, the baseline noise increased, suggesting the application of an AT derived from negatives should only be applied to samples with low levels of DNA. Further, the number and intensity of these noise peaks increased with increasing injection times, indicating that to maximize the ability to detect alleles, ATs should be validated for each post‐PCR procedure employed.     

The forensic examination of photographic equipment and materials

The scientific examination of cameras, negatives and photographic prints can provide valuable evidence. The methods used and examples of their value in criminal cases are given. The background and experience necessary to carry out this work is discussed.     

False positives and false negatives with a cocaine-specific field test and modification of test protocol to reduce false decision

The specificity of the Scott test, which is widely used in the field to detect cocaine, was investigated. Several drugs and medicines were applied to the test, and the conditions leading to false positives or false negatives were defined. The Scott test consists of three steps, each involving the addition of a certain reagent and observation of the color that consequently develops. In the first step, blue precipitates appear. In the second, these precipitates completely disappear. In the third step, blue appears again, but in the lower layer. It became clear that proper sample size is critical for correct decision, since too much heroin or dibucaine showed exactly the same color sequence as cocaine HCl and thus gave false positives, and too much cocaine HCl showed persisting precipitates in the second step, yielding a false negative. The appropriate sample size was 1mg or smaller. Freebase (crack) cocaine gave false negatives even when the sample size was appropriate, and it could not be distinguished from a newer substance of abuse, 5-methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT, foxy). The authors developed a new protocol to distinguish crack from 5-MeO-DIPT.     

Screening postmortem blood and tissues for nine classes [correction of cases] of drugs of abuse using automated microplate immunoassay

A commercially available enzyme-linked immunosorbant assay (ELISA) was evaluated as a screening procedure for the detection of nine classes of abused drugs in postmortem blood and tissue specimens. Specifically, postmortem blood, fluid and/or tissue homogenates were screened for amphetamine (AMP), methamphetamine (MET), barbiturates (BARB), benzodiazepines (BZD), cannabinoids (CNB), cocaine (benzoylecgonine; BE), morphine-specific (MOR), opiates (class; OPI), phencyclidine (PCP) and lysergic acid diethylamide (LSD) by ELISA and by coated tube radioimmunoassay (CTR) (BARB, BE, OPI, PCP, LSD) or double-antibody radioimmunoassay (DAR) (AMP/METH, BZD, CNB). Specimens that screened 'positive' by any method were confirmed and quantitated by gas chromatography/mass spectrometry (GC/MS). The only assay that appeared to perform less optimally than RIA was the MOR assay (five false negatives). However, this assay is very specific for free morphine while the GC/MS confirmation method provided a total morphine value. The OPI assay was more sensitive, producing fewer false negatives, and is recommended for broad class opiate screening. EIA is an adequate alternative to RIA for screening postmortem specimens, including blood and tissue, for nine major classes of drugs.     

A cocaine body packer with normal abdominal plain radiograms. Value of drug detection in urine and contrast study of the bowel

Drug packets are usually detected by ordinary abdominal radiographs, which is of major importance in the apprehension and prosecution of drug body packers, but false negatives may occur. We report the case of a cocaine body packer who had used the prograde route and in whom the initial abdominal plain films were normal. The diagnosis of cocaine body packing was assessed by seldom-described complementary methods of detection, including drug detection in the urine and contrast study of the bowel.     

Violence and Mental Illness: A New Analytic Approach

Empirical studies of violence and mental illness have used many different methods. Current state-of-the-art methods gather information from both subject and collateral interviews as well as official records. Typically these sources are treated as additive. Any report of a violent incident from any source is treated as true and all reported incidents are added to generate estimates of frequency. This paper presents a new statistical technique that uses the level of agreement between the sources of data to adjust those estimates. The evidence suggests that, although the additive technique for using multiple sources correctly estimates how many people are involved, it substantially underestimates the number of incidents. The new technique substantially reduces both false negatives and false positives.     

HAIRVEQ 2006: evolution of laboratories' performance after different educational actions

HAIRVEQ is a proficiency testing program for hair analysis of illicit drugs organized by the Istituto Superiore di Sanità (Rome, Italy) and the Institut Municipal d'Investigació Mèdica (Barcelona, Spain). The aim of the three exercises performed in 2006 was the evaluation of 32 laboratories' performance when analyzing the same hair sample containing opiates, cocaine and methadone, after carrying out some specific educational interventions. In the first round, the sample was sent to be analyzed following laboratory routine methodology. In the second round, standard operating procedures (SOP) for hair testing including sample preparation, method validation and qualitative and quantitative data evaluation, and an open hair sample for SOP training were also sent together with other hair samples including the one used for performance evaluation. After the second round, a workshop was held with participant laboratories to discuss methodological issues and interpretation of obtained results. An additional amount of open samples was distributed to the laboratories for implementing the SOPs. In the third round, the same unknown sample containing opiates, cocaine and methadone was resent for the final evaluation of laboratory performance. In the first round, 11 incorrect qualitative results (10 false negative and 1 false positive) were reported by seven laboratories (22%), in the second round, a reduction in the number of incorrect results was observed (4 false negatives and 1 false positive were reported by four laboratories, 13%) and in the third round, 5 false positives and 5 false negatives were reported by seven laboratories (22%). Concerning quantitative results, the scatter was similar between the three rounds and similar to the ones reported by other proficiency tests in hair analysis. More educational actions should be addressed to a group of laboratories, which did not yet show satisfying qualitative and quantitative results.     

Illuminating the benefits and limitations of forensic light sources

Forensic light sources, such as a Crime-lite, are used in forensic laboratories and by police staff in the examination for, and detection of, biological material. Whilst the benefits of using forensic light sources are relatively well understood, their limitations are less-so. This report details the outcome of studies, validation and review by three forensic laboratories, as well as three case examples, to highlight both the strengths and weaknesses of the tested forensic light sources and to demonstrate that, whilst a useful preliminary screening tool, they should not be used in isolation without subsequent presumptive chemical testing. False positives and negatives are common, and the background substrate and specific biological material present can have a significant effect on the outcome of examination when using a forensic light source.     

Dissecting Thoracic Aortic Hematoma Masquerading as Blunt Force Injury of the Neck

Discoloration of the skin of the anterior and lateral neck may raise suspicion for blunt force injury, particularly cervical compression, in an unwitnessed death. We present a case of an elderly woman with an unwitnessed death at home which highlights an external examination finding of blue/purple discoloration of the skin of the neck and links this finding with those from internal examination at autopsy. Pertinent negatives include absence of conjunctival and mucosal petechiae, absence of cutaneous abrasions of the neck, and absence of contusions of the anterior neck musculature. This case illustrates a natural disease entity, spontaneous dissection of a thoracic aortic hematoma, masquerading as blunt force injury externally and highlights the importance of having an appropriate index of suspicion when triaging jurisdictional cases for postmortem examination to accurately determine cause and manner of death.     

Children’s Allegations of Sexual Abuse: A Model for Forensic Assessment

It is important both clinically and forensically to gain information to provide an understanding of the veracity of a child’s allegations of sexual abuse. Even though it is reasonable to hypothesize that most allegations are true—children are not infallible and thus some allegations are false. A systematic model of pathways to false allegations—however rare or common—is important because so much depends on this question (i.e., both false positives and false negatives are harmful to children). We propose that there are two major pathways to false allegations of child sexual abuse: (1) the child is lying and (2) the child has a false memory due to his or her problems in information processing. We conclude by presenting a more detailed protocol for more formally evaluating these pathways to false allegations in specific cases.     

Determining the Refractive Index Variation within Panes of Vehicle Windshield Glass

Refractive indices of seven double‐paned vehicle windshields were measured to assess the variation across the pane of glass and to evaluate collection techniques for known glass standards by comparing false negative rates. Measurements were made using a Foster and Freeman GRIM3 instrument, and a minimum of 240 measurements were made per pane. The mean SD of the windshields was 0.00004. It was further determined that collecting a known sample from two different sections of a shattered windshield gave the lowest rate of false negatives when using ± 2 standard deviations to estimate the RI variation of the known glass. Additionally, refractive indices often were highest in the center of the windshield and decreased toward the left and right edges; in approximately half the sample set, the two panes of a single windshield were differentiated by one or more properties.     

Validation of LUCIO-Direct-ELISA kits for the detection of drugs of abuse in urine: application to the new German driving licence re-granting guidelines

LUCIO-Direct-enzyme linked immunosorbent assay (ELISA) tests were validated for the screening of drugs of abuse cannabis, opiates, amphetamines and cocaine in urine for the new German medical and psychological assessment (MPA) guidelines with subsequent gas chromatographic-mass spectrometric (GC-MS) confirmation. The screening cut-offs corresponding to 10 ng/mL 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), 50 ng/mL amphetamine, 25 ng/mL morphine and codeine and 30 ng/mL benzoylecgonine were chosen at the point where the number of false negatives was lower than 1%. Due to their accuracy, ease of use and rapid analysis, these ELISA tests are very promising for cases where a large proportion of the tests are expected to be negative such as for abstinence monitoring as part of the driving licence re-granting process.     

Hair analysis for opiates,cocaine and metabolites. Evaluation of a method by interlaboratory comparison

The aim of this study was to evaluate the performance of a technique for the simultaneous testing of opiates, cocaine and metabolites in hair by interlaboratory comparison. Sixteen forensic and clinical laboratories with different degrees of experience in hair analysis participated voluntarily in the study (no selection criteria were applied). The suggested analytical procedure, the one routinely used in our laboratory, consisted of incubation in HCl 0.1N (45 degrees C, overnight), solid phase extraction (with Bond Elut Certify) cartridges), derivatisation (trimethylsilyl (TMS) derivatives) and GC-MS analysis. Three different mixtures of finely cut (1 mm or less) hair were prepared using drug-users' and drug-free hair: one 'negative' sample (<0.1 ng/mg for morphine, 6-acetylmorphine (6AM), cocaine and benzoylecgonine (BE)), one 'low concentration' sample (between 0.5 and 2 ng/mg) and one 'high concentration' sample (>3 ng/mg). Accuracy and precision (CV% lower than 5.1, 9.9, 5.2, 3.8, 7.3 and 8.3% for morphine, 6AM, codeine, cocaine, BE, and methylecgonine (ME), respectively; range 0.5-5 ng/mg) of the method and homogeneity of the mixtures were evaluated in our laboratory by intraday (CV% lower than 12% for all analytes) and interday analyses (CV% lower than 17% for all analytes except 6AM, 25%). Participants in the study were grouped into: (1) laboratories (n = 6) obtaining the best qualitative and quantitative values, corresponding to those with long experience in hair analysis; (2) laboratories (n = 5) with no reported false positive and/or false negatives; (3) laboratories (n = 5) with one or more reported false positives/false negatives. The results obtained by the labs of the first group were used as reference values. The scatter of data was similar to those obtained in other published studies.     

The effect of ionizing gamma radiation on natural and synthetic fibers and its implications for the forensic examination of fiber evidence

Circumstances of criminal activities involving radioactive materials may mean fiber evidence recovered from a crime scene could have been exposed to materials emitting ionizing radiation. The consequences of radiation exposed fibers on the result of the forensic analysis and interpretation is explored. The effect of exposure to 1-1000 kGy radiation doses in natural and synthetic fibers was noticeable using comparative forensic examination methods, such as optical microscopy, microspectrophotometry, and thin-layer chromatography. Fourier transform infrared spectroscopy analysis showed no signs of radiation-induced chemical changes in any of the fiber structures. The outcome of the comparative methods highlights the risk of "false negatives" associated in comparing colors of recovered fibers that may have been exposed to unknown radiation doses. Consideration of such results supports the requirement to know the context, including the environmental conditions, as much as possible before undertaking a forensic fiber examination.