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1.
Bones fluoresce when exposed to certain wavelengths of shortwave light, and this property can be useful in locating and sorting skeletal remains in forensic contexts. The proteins in bone collagen are largely responsible for its fluorescent properties, but these proteins degrade and denature over time. This study examined the fluorescence of bones from four temporal groups (recent, semi‐recent, ancient, and historic) ranging from 0 to 1064 years before present. Specimens were photographed under 490 nm wavelength light, and fluorescence was quantified by converting intensity to a gray scale value based on the RGB color model using ImageJ® software. Significant (p < 0.05) differences were found in mean fluorescence between all four temporal groups, and a 0.324 coefficient of correlation indicates a significant (inverse) relationship between fluorescence and time. Bone fluorescence decreases with time, but some fluorescence is retained even in older samples. Fluorescence can therefore be reliably used in many modern skeletal remains searches.  相似文献   

2.
The detection of latent traces is an important aspect of crime scene investigation. Blood stains on black backgrounds can be visualized using chemiluminescence, which is invasive and requires a darkened room, or near-infrared photography, for which investigators need to change filters manually to optimize contrast. We demonstrated the performance of visible reflectance hyperspectral imaging (400–720 nm) for this purpose. Several processing methods were evaluated: single wavelength bands, ratio images, principal component analysis (PCA), and “SIMPLe-to-use Interactive Self-modeling Mixture Analysis” (SIMPLISMA). Using these methods, we were able to enhance the contrast between blood stains and 12 different fabrics. On black cotton, blood dilutions were visible with a minimal concentration of 25% of whole blood. The hyperspectral camera system used in this study is portable and wireless, which makes it suitable for crime scene use. The described technique is noncontact and nondestructive, so all traces are preserved for further analysis.  相似文献   

3.
Latent fingerprint deposits on thermal paper have been visualized noninvasively at visible wavelengths when illuminated with a UV‐A light source (peak 365 nm). A higher intensity UV source (250 W/m2 at 0.38 m) gave superior fingerprint visibility when compared with a 60 W/m2 (at 0.4 m) source. Removing the visible (blue) component of the light source emission did not adversely affect the visibility of the fingerprint. Sample fingerprints from 100 donors, when examined 24 h after deposition, produced identifiable fingerprints from nearly 34% of fingerprint deposits. A mechanism for the observed visibility is proposed based on low emission of visible wavelengths from areas of thermal paper coincident with the fingerprint deposit, when illuminated with UV. This is likely due to a weak color change in the thermal paper dye arising from protonated amino acid components of the sweat. This effect was not observed on nonthermal paper.  相似文献   

4.
During a bloodstain pattern analysis, one of the essential tasks is to distinguish between different kinds of applied forces as well as to estimate their level of intensity. In this study, high‐speed digital imaging has been used to analyze the formation of cast‐off patterns generated by a simulated backswing with a blood‐bearing object. For this purpose, 0.5 mL blood was applied evenly over the last 5 cm of a blade simulant. Bloodstains were created through the controlled acceleration of a backswing at different speed levels between 1.1 m/sec and 3.8 m/sec. The flight dynamics of blood droplets were captured with an Olympus® i‐Speed 3 high‐speed digital camera with a Nikon® AF Nikkor 50 mm f/1.8 D lens and analyzed using the Olympus i‐Speed 3 Viewer software. The video analysis showed that, during the backswing, blood droplets would move toward the lower end of the knifepoint and would be tangentially thrown off. These droplets impacted on the horizontal surface according to the arc of the swing. An increase in velocity led to longer cast‐off patterns with distinct morphological characteristics. Under laboratory conditions, bloodstain pattern analysis allows certain conclusions about the intensity of a backswing and provides instructions on the position of the offender. However, due to the number of unknown variables at a crime scene, such interpretation of cast‐off patterns is extremely limited and should be performed with extreme caution.  相似文献   

5.
Abstract: The reflection of visible light from α‐phase brass subject to surface oxidation in air at elevated temperatures is investigated. X‐ray photoelectron and auger electron spectroscopy confirm that covered areas of brass (not exposed to air) display dezincification but an absence of significant surface oxidation, confirming a differential oxidation mechanism. Visualization of differential oxidation is shown to be enhanced by selective digital mapping of colors reflected from the surface of the brass using Adobe® Photoshop®. Enhancement is optimal when the brass is heated to ~250°C with areas of oxidation having a mirror‐like appearance. The use of this enhancement method to produce a faithful image of fingerprint ridge characteristics is demonstrated on brass shell casings where fingerprints were deposited prefiring.  相似文献   

6.
Abstract: The design and preliminary characterization of a novel sensor for drugs of abuse, DETECHIP®, is described in this proof‐of‐concept note. Combining both colorimetric and fluorimetric assays, DETECHIP® is suitable for lab and field use. More than a conventional spot test which provides a single “yes or no” answer, DETECHIP® provides twenty responses for a more complete characterization of suspect material. This is accomplished by visually noting colorimetric and fluorescent changes of carefully selected dyes upon the addition of test analytes, including drugs of abuse, with respect to controls. Color and fluorescence changes are recorded numerically so that a 20 digit identification code can be constructed for comparison of test analytes and known compounds. DETECHIP® is applicable to a variety of drugs, both plant‐derived and synthetic, addressing the need to use several different spot tests simultaneously for a single sample.  相似文献   

7.
Jet‐propelled personal watercraft (PWC) or jet‐skis have become increasingly popular. The means of propulsion of PWC, which is a jet of water forced out of small nozzle at the rear of the craft, combined with a high risk of falling off of the seat and into close proximity with the water jet stream, raise the potential for a unique type of injury mechanism. The most serious injuries associated with PWC falls are those that occur when the perineum passes in close proximity to the jet nozzle and the high‐pressure water stream enters the vaginal or rectal orifice. We describe the forensic investigation into a case of an anovaginal “blowout” injury in a passenger who was ejected from the rear seat position of a PWC and subsequently suffered life‐threatening injuries to the pelvic organs. The investigation included a biomechanical analysis of the injury mechanism, a summary of prior published reports of internal pelvic injuries resulting from PWC falls as well as other water sports and activities, and a comparison of the severity of the injuries resulting from differing mechanisms using the New Injury Severity Score (NISS). The mean (±standard deviation [SD]) NISS values for reported PWC injuries [not including the NISS of 38 in this case study] were 11.2 (±9.5), while the mean value for reported water‐skiing falls was half that of the PWC group at 5.6 (±5.2). It was concluded that the analyzed injuries were unique to a PWC ejection versus other previously described non‐PWC‐associated water sport injuries. It is recommended that PWC manufacturers help consumers understand the potential risks to passengers with highly visible warnings and reduce injury risk with revised seat design, and/or passenger seat “deadman” switches.  相似文献   

8.
The purpose of this study was to identify and compare patterns of trauma associated with AutoPulse® CPR and manual CPR. Finalized autopsy records from 175 decedents brought to the Harris County Institute of Forensic Sciences were reviewed, 87 received manual‐only CPR, and 88 received AutoPulse® CPR (in combination with manual CPR as per standard protocol). The characteristic pattern observed in manual‐only CPR use included a high frequency of anterior rib fractures, sternal fractures, and midline chest abrasions along the sternum. The characteristic pattern observed in AutoPulse® CPR use included a high frequency of posterior rib fractures, skin abrasions located along the anterolateral chest and shoulder, vertebral fractures, and a few cases of visceral injuries including liver lacerations, splenic lacerations, and hemoperitoneum. Knowledge of the AutoPulse® CPR injury pattern can help forensic pathologists differentiate therapeutic from inflicted injuries and therefore avoid an erroneous assessment of cause and manner of death.  相似文献   

9.
This study investigated whether routinely used forensic tests can distinguish 3‐day‐old or 2‐week‐old fly artifacts, produced after feeding on human blood, semen, or saliva, from the biological fluid. Hemastix®, Hemident?, and Hemascein? were unable to distinguish blood from artifacts. Hemastix® returned false positives from negative controls. ABAcard® Hematrace® and Hexagon OBTI could distinguish blood from 3‐day‐old artifacts, but not 2‐week‐old artifacts. Phadebas® and SALIgAE® were unable to distinguish saliva from artifacts. RSID?‐Saliva was able to distinguish saliva from 3‐day‐old artifacts, but not 2‐week‐old artifacts. Semen tests Seminal Acid Phosphatase, RSID?‐Semen, and ABAcard® p30 were all able to distinguish semen from 3‐day‐old artifacts, but not 2‐week‐old artifacts. The tests investigated cannot be relied upon to distinguish artifacts from biological fluids. However, if an artifact is identified by its morphology, a positive result may indicate which biological fluid the fly consumed, and this knowledge may prove useful for investigators searching for DNA.  相似文献   

10.
11.
Psilocybe cubensis, or “magic mushroom,” is the most common species of fungus with psychedelic characteristics. Two primer sets were designed to target Psilocybe DNA using web‐based software and NBCI gene sequences. DNA was extracted from eighteen samples, including twelve mushroom species, using the Qiagen DNeasy® Plant Mini Kit. The DNA was amplified by the polymerase chain reaction (PCR) using the primers and a master mix containing either a SYBR® Green I, Radiant? Green, or LCGreen Plus® intercalating dye; amplicon size was determined using agarose gel electrophoresis. The PCR assays were tested for amplifiability, specificity, reproducibility, robustness, sensitivity, and multiplexing with primers that target marijuana. The observed high resolution melt (HRM) temperatures for primer sets 1 and 7 were 78.85 ± 0.31°C and 73.22 ± 0.61°C, respectively, using SYBR® Green I dye and 81.67 ± 0.06°C and 76.04 ± 0.11°C, respectively, using Radiant? Green dye.  相似文献   

12.
The purpose of this study was to determine the factors affecting the accuracy of 3D models and 3D prints of cranial blunt force trauma, to evaluate the applicability and limitations of modeling such injuries. Three types of cranial blunt force lesions were documented (hinge, depressed, and comminuted) using three forms of surface scanning (laser, structured light scanner, and photogrammetry) at two different quality settings (standard and high). 3D printed models of the lesions were produced using two different materials (a gypsum‐like composite powder called VisiJet® PXL and an acrylic engineered composite plastic called VisiJet® M3 in crystal colour). The results of these analyzes indicate the prints in this study exhibit some statistically significant differences from the actual bone lesions, but details of the lesions can be reproduced to within 2 mm accuracy.  相似文献   

13.
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.  相似文献   

14.
Visualization of fingerprint deposits by digital color mapping of light reflected from the surface of heated brass, copper, aluminum, and tin has been investigated using Adobe® Photoshop®. Metals were heated to a range of temperatures (T) between 50°C and 500°C in 50°C intervals with enhancement being optimal when the metals are heated to 250°C, 350°C, 50°C, and 300°C, respectively, and the hue values adjusted to 247°, 245°, 5°, and 34°, respectively. Fingerprint visualization after color mapping was not degraded by subsequent washing of the metals and color mapping did not compromise the visibility of the fingerprint for all values of T. The optimum value of T for fingerprint visibility is significantly dependent of the standard reduction potential of the metal with Kendall's Tau (τ) = 0.953 (p < 0.001). For brass, this correlation is obtained when considering the standard reduction potential of zinc rather than copper.  相似文献   

15.
Although prior research has had a tendency to confirm a negative association between religiousness and crime, criminologists have been slow to incorporate new concepts and emergent issues from the scientific study of religion into their own research. The self‐identity phrase “spiritual but not religious” is one of them, which has been increasingly used by individuals who claim to be “spiritual” but disassociate themselves from organized religion. This study first examines differences in crime between “spiritual‐but‐not‐religious” individuals and their “religious‐and‐spiritual,” “religious‐but‐not‐spiritual,” and “neither‐religious‐nor‐spiritual” peers in emerging adulthood. Specifically, we hypothesize that the spiritual‐but‐not‐religious young adults are more prone to crime than their “religious” counterparts, while expecting them to be different from the “neither” group without specifying whether they are more or less crime prone. Second, the expected group differences in crime are hypothesized to be explained by the microcriminological theories of self‐control, social bonding, and general strain. Latent‐variable structural equation models were estimated separately for violent and property crimes using the third wave of the National Longitudinal Study of Adolescent Health. The overall results tend to provide a partial support for the hypotheses. Implications for criminology and future research are discussed.  相似文献   

16.
Dextromethorphan (DXM) is abused most commonly among adolescents as a recreational drug to generate a dissociative experience. The objective of the study was to assess driving with and without DXM ingestion. The effects of one‐time maximum daily doses of DXM 120 mg versus a guaifenesin 400 mg dose were compared among 40 healthy subjects using a crossover design. Subjects’ ability to drive was assessed by their performance in a driving simulator (STISIM® Drive driving simulator software) and by conducting a standardized field sobriety test (SFST) administered 1‐h postdrug administration. The one‐time dose of DXM 120 mg did not demonstrate driving impairment on the STISIM® Drive driving simulator or increase SFST failures compared to guaifenesin 400 mg. Doses greater than the currently recommended maximum daily dose of 120 mg are necessary to perturb driving behavior.  相似文献   

17.
East Timor is a country located in Southeast Asia. In this study, we determined allele frequencies and forensic parameters for 24 STR autosomal loci included in the PowerPlex® Fusion System. Autosomal STR data was collected from saliva samples of 100 individuals from East Timor. The amplification of the 24 autosomal STRs was performed using PowerPlex® Fusion System (Promega Corporation) and the amplified products were analysed on 3500 Genetic Analyser using GeneMapper® ID-X 1.2 Software (Applied Biosystems). All the analysed loci meet Hardy–Weinberg equilibrium after Bonferroni correction. In our samples, we found “off-ladder” alleles (D2S441, Penta E and FGA locus) confirmed by reamplification, amplification with others kits and sequenced when justified.  相似文献   

18.
Bloodstain photography is important in forensic applications, especially for bloodstain pattern analysis. This study compares the enhancement effect of bloodstain photography using three different types of light source: fluorescent white light, near‐ultraviolet (UV) light‐emitting diode (LED) light, and 410 nm LED light. Randomized complete block designs were implemented to identify the lighting that would statistically produce the best enhancement results for bloodstains on different types of surfaces. Bloodstain samples were prepared on white cotton, brown carpet, tar road, and wood. These samples were photographed in darkroom conditions using a Canon EOS 50D digital SLR camera, with Canon EFS 60 mm f/2.8 Macro USM lens. Two‐way analysis of variance and Fisher's least significant difference test were used to analyze the contrast of the images. The statistical analysis showed that 410 nm light is the best among the tested lights for enhancing bloodstains on the tested surfaces, where the contrast of bloodstain to background was the highest.  相似文献   

19.
Blood spatter analysis is an important step for crime scene reconstruction. The presence of saliva in blood spatter could indicate expectorated blood which is difficult to distinguish from impact spatter. In this study, four saliva test methods (SALIgAE®, Phadebas® sheet, RSID-Saliva kit, and starch gel diffusion) were compared to identify the best method for detecting expectorated blood spatter. The RSID-Saliva kit showed the highest sensitivity even when saliva was mixed with blood, and was not inhibited by the presence of blood. The SALIgAE® test provided easy and rapid results, but the yellow color of a positive reaction was overwhelmed by the red color of the blood. The starch gel diffusion method and the Phadebas® sheet exhibited relatively low sensitivity and the assay took a long time. When using the RSID-Saliva kit for identifying saliva in blood, results should be read within 10 min.  相似文献   

20.
Although the governments of the United States and Japan differ markedly in racial ideology, official crime statistics in both nations reflect political arrangements which marginalize minority populations. In both nations, official crime statistics reveal more about the attempts of majority populations to label minority populations as a criminal class than about variations in criminal behavior across racial populations. While there is no racially pure Black population in the United States, there is a “black” category within official statistics, and the statistics are used to justify crime control policies which have a disparate impact on the diverse peoples who are socially‐perceived as Black. While there are undeniably non‐Japanese populations in Japan, there are no racial categories for them in official statistics which define them out of existence; except where crime statistics are concerned, so that the police can monitor the criminality of “foreigners.” In both societies, official categorization of race in crime statistics implies that crime is a minority problem; government statistics reinforce official ideology that crimes by “foreigners” and “black violence” are the real threats to civil society.  相似文献   

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