An analysis of Korean homicide crime-scene actions

Recent studies have focused on how different styles of homicides will be reflected in the different types of behaviors committed by offenders at a crime scene. It is suggested that these different types of behaviors best be understood using two frameworks, expressive/instrumental aggression and planned/unplanned violence, to analyze the way the offender acts at the crime scene. Multidimensional analysis is carried out on the crime-scene actions of 70 Korean homicides. The proposed frameworks are found to be a useful way of classifying homicide offenses, assigning 80% of homicides to a dominant theme. Results also indicate that behavioral differences can be related to the differences in the offender-victim relationship. Finally, implications and suggestions for future research are discussed.     

Sex determination from the talus of Koreans by discriminant function analysis

The aims of this study were to investigate the sex discriminating potential of the talus in Koreans and compare this with other analyses in different populations. Statistical analyses were performed using data from nine measurements acquired from 140 tali (70 men, 70 women). The talus of Koreans is dimorphic between sexes in all measurements (p < 0.01). Discriminant function equations were generated by univariate, multivariate, and stepwise methods with a range of accuracy from 67.1 to 87.1%. Stepwise equations of other populations did not discriminate the sex of the Korean sample as accurately as each equation's own accuracies. The variables with high accuracy in this study are useful for sex determination of Koreans on the basis of confirmation of population specificity.     

An explanation for camera perspective bias in voluntariness judgment for video-recorded confession: Suggestion of cognitive frame

Three experiments were conducted to test the hypothesis that difference in voluntariness judgment for a custodial confession filmed in different camera focuses ("camera perspective bias") could occur because a particular camera focus conveys a suggestion of a particular cognitive frame. In Experiment 1, 146 juror eligible adults in Korea showed a camera perspective bias in voluntariness judgment with a simulated confession filmed with two cameras of different focuses, one on the suspect and the other on the detective. In Experiment 2, the same bias in voluntariness judgment emerged without cameras when the participants were cognitively framed, prior to listening to the audio track of the videos used in Experiment 1, by instructions to make either a voluntariness judgment for a confession or a coerciveness judgment for an interrogation. In Experiment 3, the camera perspective bias in voluntariness judgment disappeared when the participants viewing the video focused on the suspect were initially framed to make coerciveness judgment for the interrogation and the participants viewing the video focused on the detective were initially framed to make voluntariness judgment for the confession. The results in combination indicated that a particular camera focus may convey a suggestion of a particular cognitive frame in which a video-recorded confession/interrogation is initially represented. Some forensic and policy implications were discussed.     

The suitability of using domestic pigs (Sus spp.) as human proxies in the geophysical detection of clandestine graves

Research in many forensic science fields commonly uses domestic pigs (Sus spp.) as proxies for human remains, due to their physiological and anatomical similarities, as well as being more readily available. Unfortunately, previous research, especially that which compares the decompositional process, has shown that pigs are not appropriate proxies for humans. To date, there has not been any published research that specifically addresses whether domestic pigs are adequate human proxies for the geophysical detection of clandestine graves. As such, the aim of this paper was to compare the geophysical responses of pig cadavers and human donor graves, in order to determine if pigs can indeed be used as adequate human proxies. To accomplish this, ground penetrating radar (GPR) and electrical resistivity tomography (ERT) responses on single and multiple pig cadaver graves were compared to single and multiple human donor graves, all of which are in known locations within the same geological environment. The results showed that under field conditions, both GPR and ERT were successful at observing human and pig burials, with no obvious differences between the detected geophysical responses. The results also showed that there were no differences in the geophysical responses of those who were clothed and unclothed. The similarity of the responses may reflect that the geophysical techniques can detect graves despite what their contents are. The study implications suggest that experimental studies in other soil and climate conditions can be easily replicated, benefiting law enforcement with missing persons cases.     

Comparison of feature selection and data fusion of Fourier transform infrared and Raman spectroscopy for identifying watercolor ink

The identification of different kinds of watercolor inks is an important work in the field of forensic science. Four different kinds of watercolor ink Spectroscopy data fusion strategies (Fourier Transform Infrared spectroscopy and Raman spectroscopy) combined with a non-linear classification model (Extreme Learning Machine) were used to identify the brand of watercolor inks. The study chose Competitive Adaptive Reweighted Sampling (CARS), Random Frog (RF), Variable Combination Population Analysis-Genetic Algorithm (VCPA-GA), and Variable Combination Population Analysis-Iteratively Retains Informative Variables (VCPA-IRIV) to extract characteristic variables for mid-level data fusion. The Cuckoo Search (CS) algorithm is used to optimize the extreme learning machine classification model. The results showed that the classification capacity of the mid-level fusion spectra model was more satisfactory than that of single Infrared spectroscopy or Raman spectroscopy. The CS-ELM models based on infrared spectroscopy used to recognize the watercolor ink according to brands (ZHENCAI, DELI, CHENGUANG, and STAEDTLER) obtained an accuracy of 66.67% in the test set using all spectral datasets. The accuracy of CS-ELM models based on Raman spectroscopy was 67.39%. The characteristic wavelength selection algorithms effectively improved the accuracy of the CS-ELM models. The classification accuracy of the mid-level spectroscopy fusion model combined with the VCPA-IRIV algorithm was 100%. The data fusion method increased effectively spectral information. The method could satisfactorily identify different brands of watercolor inks and support the preservation of artifacts, paintings, and forensic document examination.     

Toward multidimensional information: A derivatization-free UHPLC-QqQ MS/MS method for amino acid components of fingerprint

The analysis of fingerprint chemical composition is a meaningful way to excavate the multidimensional information of fingerprint, including the donor profiling information and the age of a fingerprint, which broadens the evidential values of fingerprint, especially for the partial and distorted fingerprint. But the research remains still in the pilot phases or is ongoing. Amino acids are the dominant organic substances in latent sweat fingerprint and influenced by many donor factors. Hence, their content reflects personal information of donors. Forensic science will be revolutionized if suspects can be individualized by their amino acid content. The diverse nature, distinct physicochemical properties, and ultra-micro levels of amino acids present in fingerprints make it hard to detect. A high sensitivity method for detecting and quantifying multiple amino acid components is required. UHPLC-QqQ MS/MS offers high sensitivity, high separation, simultaneous multicomponents detection, and no derivatization, making it an ideal method for detecting and analyzing amino acids in fingerprints. Therefore, in this study, we propose and validate an efficient UHPLC-QqQ MS/MS method for the extraction and analysis of 13 amino acids from fingerprint. We compared the results of amino acids of 10 different substrates and found that the inherent amino acids in most porous substrates would have been extracted along with the fingerprint amino acids, making them unsuitable for quantitative amino acid analysis. Instead, plastic sheets are ideal substrates for laboratory studies. Then, extensive experiments were conducted among 30 donors for multidimensional information analysis. The type of samples analyzed were eccrine-rich fingerprints. A Binary Logistic Regression (BLR) model was developed, and the female and male donors were successfully differentiated by amino acids in fingerprints. Two other mathematical models were also developed to verify the accuracy, and all three different mathematical models were able to identify donors of different genders with over 90% accuracy. This demonstrates that amino acids have the potential to provide more information for donors as metabolic markers. In the future, we will conduct a series of experiments to analyze more multidimensional information for individual identification by amino acid content in the fingerprint.     

Application of Micro‐Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy to Ink Examination in Signatures Written with Ballpoint Pen on Questioned Documents

Questioned documents examined in a forensic laboratory sometimes contain signatures written with ballpoint pen inks; these signatures were examined to assess the feasibility of micro‐attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy as a forensic tool. Micro‐ATR FTIR spectra for signatures written with 63 ballpoint pens available commercially in Korea were obtained and used to construct an FTIR spectral database. A library‐searching program was utilized to identify the manufacturer, blend, and model of each black ballpoint pen ink based upon their FTIR peak intensities, positions, and patterns in the spectral database. This FTIR technique was also successfully used in determining the sequence of homogeneous line intersections from the crossing lines of two ballpoint pen signatures. We have demonstrated with a set of sample documents that micro‐ATR FTIR is a viable nondestructive analytical method that can be used to identify the origin of the ballpoint pen ink used to mark signatures.     

A novel chitosan/tripolyphosphate/L‐lysine conjugates for latent fingerprints detection and enhancement

Most chemical and physical methods employed in visualizing latent marks have shown detrimental effects on human health and, therefore, some research groups have directed their attention to the utilization of various (bio)polymers with the aforementioned purpose. Although chitosan is widely used in medicine, pharmacy, food, and drug delivery systems, there are very few studies that address this biopolymer utilization in forensic applications, such as the detection of latent fingerprints. We used chitosan crosslinked with sodium tripolyphosphate and conjugated with L‐lysine to enhance the visualization of latent fingerprints, due to its ability to interact with fingerprint sweat residues. These conjugates were prepared using different (w/w) amounts of chitosan and tripolyphosphate (6/1; 4/1; 1/1; 1/4; and 1/6), and those with the most promising results (i.e., 6/1 formulation) were investigated in detail. Fourier transform infrared (FT‐IR) spectroscopy confirmed interactions between components of the systems. Optical microscopy and scanning electron microscope (SEM) analysis showed that prepared powder formulations were uniform in size and confirmed that chitosan/tripolyphosphate/lysine conjugates bind easily to the sweat and lipid residues present in the latent fingerprints. The testing of prepared conjugates demonstrated the potential of these systems as bio‐based powder substitution for commercially available powders.