Remote spectroscopic identification of bloodstains

Blood detection and identification at crime scenes are crucial for harvesting forensic evidence. Unfortunately, most tests for the identification of blood are destructive and time consuming. We present a fast and nondestructive identification test for blood, using noncontact reflectance spectroscopy. We fitted reflectance spectra of 40 bloodstains and 35 nonbloodstains deposited on white cotton with spectroscopic features of the main compounds of blood. Each bloodstain was measured 30 times to account for aging effects. The outcome of the blood measurements was compared with the reflectance of blood-mimicking stains and various body fluids. We found that discrimination between blood and nonblood deposited on white cotton is possible with a specificity of 100% and a sensitivity of 98%. In conclusion, a goodness of fit between the sample's reflectance and the blood component fit may allow identification of blood at crime scenes by remote spectroscopy.     

A Study of Fatal and Nonfatal Hangings

Approximately 50% of all suicides performed worldwide are strangulations. This article presents options for the medicolegal examination of hanging. The pathogenetic mechanisms and clinical pictures of victims are discussed. Examples of the process of diagnosis and expert conclusions are given. This article is intended for physicians and forensic pathologists. The literature focusing on asphyxia by strangulation is reviewed. Data from Vilnius Hospitals and the State Forensic Medicine Service concerning strangulations performed between 2012 and 2014 are analyzed and include the findings of 5650 autopsies (36% asphyxia) and 4 survived victims. The predominant symptoms were neurological, cardiovascular, and respiratory symptoms. After asphyxia, patients should consult by a psychiatrist, ophthalmologist, gastroenterologist, and endocrinologist. A ligature mark was the most observable sign of asphyxia by neck strangulation. Only complications in the poststrangulation period were treated. Mechanical asphyxia must be identified as the main injury in the clinical diagnosis and encoded as ICD‐10.     

Crises and their interpretations

Crises are interpreted facts. Thus the sociological term crisis implies that a certain period of economic and political development has been in practice already interpreted as a crisis. Therefore the comparison between the crises 1929 ff. (the beginning of the first world economic crisis and the beginning of the destruction of the first Austrian Republic) and 1974 (the first oilprizeshock and the end of full employment in Western Europe) in Austria must consider two dimensions. First, the authors compare some key-data of the economic and political development. Second, they compare interpretations of the crises by analyzing articles from two Austrian newspapers in each period. The comparison shows-as expected-important differences between the two crises. But it also draws the attention to some unexpected similarities.     

Collecting touch DNA from glass surfaces using different sampling solutions and volumes: Immediate and storage effects on genetic STR analysis

Touch DNA has become increasingly important evidence in todays' forensic casework. However, due to its invisible nature and typically minute amounts of DNA, the collection of biological material from touched objects remains a particular challenge that underscores the importance of the best collection methods for maximum recovery efficiency. So far, swabs moistened with water are often utilized in forensic crime scene investigations for touch DNA sampling, even though an aqueous solution provokes osmosis, endangering the cell's integrity. The aim of the research presented here was to systematically determine whether DNA recovery from touched glass items can be significantly increased by varying swabbing solutions and volumes compared with water-moistened swabs and dry swabbing. A second objective was to investigate the possible effects of storage of swab solutions prior to genetic analysis on DNA yield and profile quality when stored for 3 and 12 months, as is often the case with crime scene samples. Overall, the results indicate that adapting volumes of the sampling solutions had no significant effect on DNA yield, while the detergent-based solutions performed better than water and dry removal, with the SDS reagent yielding statistically significant results. Further, stored samples showed an increase in degradation indices for all solutions tested, but no deterioration in DNA content and profile quality, allowing for unrestricted processing of touch DNA samples stored for at least 12 months. One further finding was a strong intraindividual change in DNA amounts observed over the 23 deposition days which may be related to the donor's menstrual cycle.     

Form follows function: Applying photographic content analysis to forensic firearm identification

Drawing forensic conclusions from an image or a video is known as “photographic content analysis.” It involves the analysis of an image, as well as objects, actions, and events depicted in images or video. In recent years, photographic depictions of objects suspected as illegal firearms have substantially increased, appearing on CCTV surveillance footage, captured by mobile phones and shared on social media. However, the law in Israel states that a person can be charged with illegally possessing a firearm only if it can be proven that the object is capable of shooting with lethal bullet energy. This becomes more challenging in cases where the firearm was not physically seized, and the evidence exclusively consists of images and video. In this study, photographic content analysis was applied to images and video where objects suspected as commercial or improvised firearms had been depicted. An image and event sequence reconstruction video databases of both firearms and replicas were created in order to better define firearm-specific functional morphological features. We demonstrate that it is possible to classify an object as a firearm by analyzing the functional, and not only the esthetic, morphology in images and video. It is also shown that event sequence reconstruction in video may be used to infer that an object suspected as a firearm has the capacity to shoot by confirming the occurrence of a shooting act or shooting process. Thus, photographic content analysis may be used to forensically establish that an object depicted in an image or a video is a firearm by ruling out other known scenarios, and without physically seizing it.     

The use of liquid latex as a pre-treatment to recover debris-covered latent fingerprints from exterior surfaces of vehicles

This study evaluated the effectiveness of using liquid latex as a pre-treatment for fingerprint recovery from the exterior surfaces of vehicles in summer. The sample of this study was 540 sebaceous latent fingerprints deposited on the lower body of three vehicles. Thirty control and thirty experimental fingerprints were deposited on each vehicle, and the experiment was repeated three times. The three vehicles were driven daily for either 2, 3, or 4 weeks after the deposition of fingerprints. After the vehicles reached their designated debris accumulation duration, the latent fingerprints in the control groups were developed with black fingerprint powder. Liquid latex was applied onto the fingerprints in the experimental groups, and they were subsequently developed with black fingerprint powder. A chi-sure test indicated that there was a significant difference in fingerprints recovery performance between two methods (X² = 4.903, d.f. = 1, p = 0.027). An odds ratio test indicated the control method increases the probability of fingerprint recovery by 1.54 times. A Fisher's exact test was used to evaluate the quality of fingerprints recovered from both methods and it indicated that there is no significant difference in quality using the two methods (p = 0.058). This study indicated that the traditional fingerprint powder method performed better for fingerprint recovery from exterior surfaces of vehicles in summer.