An examination of handwritten signatures forged using photosensitive signature stamp

Signature examination is the most common examination performed by any document examiner. Determination of the authenticity of a handwritten signature on a questioned document is an important task for forensic document examiners in the forensic science field. As a result of continuous developments in technology, a signature stamp can now be created using a photosensitive seal to enable the reproduction of a handwritten signature. These stamps are commonly used in China and several other countries. In this study, 10 types of black photosensitive stamp-pad ink, 10 brands of fountain pen ink, 15 types of black gel ink and six types of black erasable gel ink found on the Chinese domestic market were collected and 10 photosensitive signature stamps were created using the signatures of 10 people. Microscopic analysis, infrared (IR) and fluorescence analyses and microspectrophotometry (MSP) techniques were used to examine the resulting photosensitive signature stamp impressions when applied to printing papers, writing papers and invoice papers. By comparing the printing and spectral characteristics of the photosensitive signature stamp impressions with those of the signatures executed using the fountain pens, gel pens and erasable gel pens, it was possible to determine whether each signature was written or stamped using a photosensitive signature stamp. To validate these results, a 96.7% absolute accuracy and a 99.3% detection rate were achieved over a total of 150 blind tests conducted by five forensic document examiners, thus demonstrating that a combination of the four analysis methods used in this work can provide a more scientific approach and improve the accuracy and the detection rate of the examination process.

KEY POINTS

• A signature stamp is a photosensitive seal made in the style of a handwritten signature.
• Although microscopic analysis can usually provide better examination results, a comprehensive examination method that includes microscopic analysis and ink composition analysis is required to improve the accuracy and the detection rate of the examination process.
• This study collected and tested photosensitive stamp-pad inks, fountain pen inks, gel inks and erasable inks.
• Infrared and fluorescence analyses and microspectrophotometry were able to distinguish the photosensitive ink from both erasable ink and fountain pen ink.

Supplemental data for this article are available online at https://doi.org/10.1080/20961790.2021.1898755.     

科举制对台湾社会的影响

科举制是中国历史上延续最久、影响最大的文官任用考试制度。尽管科举制有许多弊病,但却提供了底层社会精英经由读书进入官场的机会,在一定程度上扩大了封建王朝的统治基础,破除了原由豪门士族把持国家政权的局面,这对中国历代政治、经济、文化、教育与社会风气,产生了久远的影响。科举制是中华政治文化中重要的一环,曾对人类政治文明的演进做出过重要贡献。科举制直接催生了不论门第的士大夫阶级的形成,间接衍生了台湾自清朝中叶进入文治阶段。在现代社会,科举精神仍在一定程度上影响着台湾社会的发展。     

傅里叶变换红外光谱技术在死亡时间推断中的运用

死亡时间(postmortem interval,PMI)推断是命案现场首先要解决的重要问题之一,因此法医学者运用了大量的技术和统计学方法试图精确推断PMI.由于PMI推断受到外部、内部、死亡前和死亡后等多种因素影响,既往多种方法均存在局限性.傅里叶变换红外(Fourier transform infrared,FTIR)光谱技术已应用于蛋白质、核酸、碳水化合物的纯品物质研究上,近年来也被广泛用于研究复杂的细胞和组织.功能强大的计算机软件可以对光谱变换、平滑、基线校正、归一化等进行处理,使FTIR光谱仪对样本的定量研究成为可能,并从分析化学领域推广到生物学和临床医学研究.本文综述了FTIR光谱原理及其在生物医学中的应用,并着重阐述死后尸体组织的FTIR光谱学变化及在PMI推断中的应用价值.     

Cognitive biases in the peer review of bullet and cartridge case comparison casework: A field study

ObjectiveForensic judgments and their peer review are often the result of human assessment and are thus subjective and prone to bias. This study examined whether bias affects forensic peer review.HypothesesWe hypothesized that the probability of disagreement between two forensic examiners about the proposed conclusion would be higher with “blind” peer review (reviewer saw only the first examiner’s comparison photos) than with “non-blind” peer review (reviewer also saw the first examiner’s interpretation and proposed conclusion). We also hypothesized that examiners with a higher perceived professional status would have a larger effect on the reported conclusion than examiners with a lower status.MethodWe acquired data during a non-blind and a blind peer review procedure in a naturalistic, covert study with eight examiners (3–26 years of experience). We acquired 97 conclusions of bullet and cartridge case comparisons in the blind and 471 in the non-blind peer review procedure.ResultsThe odds of disagreement between examiners about the evidential strength of a comparison were approximately five times larger (95%-CI [3.06, 8.50]) in the blind than in the non-blind procedure, with disagreement about 42.3% and 12.5% of the proposed conclusions, respectively. Also, the odds that their proposed conclusion was reported as the final conclusion were approximately 2.5 higher for the higher-status examiners than for lower-status examiners.ConclusionsOur results support both the hypothesis that bias occurs during non-blind forensic peer review and the hypothesis that higher-status examiners determine the outcome of a discussion more than lower-status examiners. We conclude that blind peer review may reduce the probability of bias and that status effects have an impact on the peer reviewing process.     

高等职业教育计算机专业考试改革的探析与实践

以高职教育课程考试改革为主题,对存在考试弊端进行全面剖析,提出了以素质教育为中心的考试改革思路,在教学中实践结合计算机类专业的课程考试,根据不同课程的教学特点设计了专门的课程考试改革实施方案,收到了较好的效果。     

司法职业资格考试制度及其相关问题研究

我国司法职业资格考试制度的确立对于提升我国司法职业群体的职业素质和推动司法职业群体的职业化进程具有重要意义.但从司法职业资格考试制度和司法制度以及高等法学教育的关系的维度分析,我国司法职业资格考试的制度设计存在明显缺陷.因此,借鉴国外有关国家的有益经验,进一步完善我国司法职业资格考试制度是十分必要的.     

对现场变形手印检验的探研

检验现场变形手印,必须研究其形成的原因及其变化规律,对其细节特征“差异”进行“校正”,恢复其本来面目,以利拓宽手印检验的范围。     

Detection of Inflicted Bruises by Alternate Light: Results of a Randomized Controlled Trial

Bruises are often difficult to detect on victims of violence, potentially impacting investigation and prosecution. The purpose of our randomized controlled trial was to measure the effectiveness of an alternate light source (ALS) within visible and long ultraviolet spectrums at improving bruise detection compared to white light over time. We also examined the effects of skin color, age, gender, localized fat, and injury mechanism on bruise detection. Participants included 157 healthy adults with balanced sampling across six skin color categories. Bruises were created under the controlled application of a paintball pellet and dropped weight to one upper and lower arm, respectively. Using a crossover design, both bruises were examined 21 times over 4 weeks. Ten different wavelength (350–535 nm) and filter (yellow, orange, red) combinations were used. Multilevel models were used to analyze 2903 examinations on both upper and lower arms. Results in multivariable models showed after controlling for other covariates 415 and 450 nm using a yellow filter had greater odds of detecting evidence of bruising than white light (Upper Arm: 415 nm: OR = 5.34, 95% CI: 4.35–6.56; 450 nm: OR = 4.08, 95% CI: 3.36–4.96). Under either light source, being female and having more localized fat had increased odds of detecting bruises created by the dropped weight (female: OR = 2.96, 95% CI: 2.37–3.70; fat: OR = 1.21, 95% CI: 1.09–1.34). Our results support ALS as an appropriate tool to enhance concurrent physical assessment of bruises in the presence of known history of injury. Future development and evaluation of clinical practice guidelines for ALS application are needed.     

Increasing Methamphetamine Detection in Cases of Early Childhood Fatalities

Age and organ maturity can influence drug toxicity in children; however, most clinical data and literature are based on drug concentrations in adults. Therefore, the interpretation of drugs detected in children is often difficult or not possible. Retrospective reviewing of pathology and toxicology information from postmortem cases may assist in future interpretations or identify drug trends. A search of the Forensic Science SA case files was undertaken over 15 years from January 2002 to December 2016 for all children (<13 years). Of the 412 pediatric coronial cases, toxicological information was available on 373. At least one drug was detected in 94 cases with paracetamol, ibuprofen, codeine and hospital-administrated lignocaine and morphine among the most commonly detected agents. Methamphetamine, one of the most commonly abused illicit drugs in Australia, was found in seven cases. In the methamphetamine cases, deaths were associated with shared sleeping in three, pneumonia in one, and stillbirth in one. Methamphetamine was considered potentially contributory to death in two cases. The causes of death in the remaining two cases were undetermined. As six of the seven positive cases occurred in the 2012–2016 (n = 106) timeframe, an increase has occurred over recent years in the number of infants and young children presenting to forensic autopsy in South Australia who have detectable concentrations of methamphetamine. If this is an indication of a more generalized increased childhood exposure in the community there may be significant long-term physical and psychological effects.