Volume 19. Number 1
December 2020

Original Articles

Complex Insect Fauna Found on Carcass in A Suicide Case in Taiwan 

Wei-Lun Yan; Qi-Ren Chen; Chiou-Herr Yang

Abstract¡GA male corpse was found in a park, located in an urban residential area in Taiwan. The insect data collected from this remain shows that there was an unusual insect fauna on the corpse for an outdoor case. There were three features for the entomology study in this forensic case. First, the fauna of the collected insects was more diverse than in other cases. Chrysomya rufifacies (Macquart, 1842), Synthesiomyia nudiseta (Van Der Wulp, 1883), Chrysomya megacephala (Fabricius, 1794), Sarcophaga dux (Thomson, 1869) and Fannia pusio (Wiedemann, 1830) were found on the corpse. The dominant species was S. nudiseta which is usually found on indoor human corpse. It was the first case of larvae of S. nudiseta and F. pusio found on outdoor human remains in Taiwan. Second, the Minimum Post-Mortem Interval (minPMI) was estimated to be about 10-14 days base on the develop- mental data of three species of fly, including S. nudiseta (pupae), C. megacephala (flies), S. dux (pupae). Third, fly artifacts were found on the body and clothes, and those tiny spots were thought to be blood splatter patterns, which puzzled the investigators and so they were not sure whther it was a suicide case. After careful examination, these spots were identified to be fly artifacts and thus solved the confusing. Distinguishing between fly artifacts and bloodstain patterns is important for the crime scene inves- tigation. It excluded the wrong information from the bloodstain-like spot (fly artifacts), allowing more attention on other evidence analysis.

An Improvement of the Interpretability for the Deep Learning Based Signature Examination Assistance Method

Hsin-Hsiung Kao; Che-Yen Wen; Kai-Ping Chang

Abstract¡G Automatic signature verification has been extensively researched for a long time and has already been used in many fields like banking, security, and other authentication purposes. However, human experts still play a dominant role in the field of forensic handwriting examination. Only a few studies have been conducted on the use of computers in assisting handwriting experts. There are also fewer attempts to perform the examination based on only a single known sample. We built a deep learning based assistance method for signature examination in our previous work. The method can deal with the problem of signature verification by single known sample, and is based on an explainable deep learning approach (by using deep convolutional neural network, DCNN). This paper is a continuation and refinement of our previous work. We refine the interpretability of the model and present application scenarios for assisting signature examination. After improving the interpret- ability of the model, the proposed method can be used as an assistant system by providing quantitative results. The visualized heatmaps can also be used to identify genuine or suspicious strokes in disputed signatures.


Proteins: A New Alternative for Postmortem Interval Measurements

Sachil Kumar; Paurabhi Singh; Sangram Sandhu

Abstract¡G Precise knowledge of the time since death has immense legal, psychological and criminological impact. In spite of the impor- tance of postmortem interval estimation, it is not feasible to measure exactly the time since death over 36 hours till 72 hours or above. Due to an emerging era, several advancement and discoveries are witnessed in the field of biochemistry. The new targets are RNA (Ribonucleic acid), DNA (Deoxyribonucleic acid) and various proteins. Protein biomarkers are precisely governed while in the living body and assumption on fading with time after the death. This paper provides a compilation of research available in the literature on postmortem protein breakdown and reviews their use as post-mortem interval markers in order to provide guid- ance for forensic pathologists.

Deepfake Detection Based on No-Reference Image Quality Assessment (NR-IQA)

Wen-Chao Yang; Jhou-Chang Tsaig

Abstract¡GThe deepfake technique has been shown its capability of replacing the actor¡¦s face in movie episodes or imitating the voice of an actor whose vocal cord is damaged. Due to the rapid development of digital technology, the use of deepfake images or videos has the capability of deceiving human eyes and computer programs with complex algorithms. However, malicious uses of this technology will seriously endanger national security and social stability. Recently, due to the widespread use of multimedia on the Internet, no-reference image quality assessment (NR-IQA) research- es are popular. NR-IQA techniques are the image quality assessment methods without the reference images. That is useful for evaluating the image and video quality in social media. In this paper, we propose a novel deepfake detection method based on NR-IQA techniques. According to the experimental results, the detection rate of the proposed method is about 66.67%. Besides, we find out the resolution of deepfake videos should be another important factor to be considered..

Forensic Analysis of Red Nail Polishes by FT-IR Microspectroscopy¡VA Preliminary Study

Li-Ling Cho; I-Chun Lee

Abstract¡G In the sexual assault, murder or other violence cases, nail polishes are a type of transfer evidence that can be commonly found at the crime scene [1-4]. The chemical analysis of nail fragments coated with nail polish, or other items with nail polish smear can offer useful information to assist in a crime reconstruction. The components of the nail polishes vary according to their brand, color and purpose of the products. FT-IR microspectroscopy offers a nondestructive method of trace evidence and uses in major- ity of forensic laboratories. In this study, 14 red nail polishes with 8 different brands were obtained and evaluated using FT-IR microspectroscopy. The results showed that 14 red nail polishes can be visually classified into 12 groups by infrared spectra with a discriminating power of 0.978. The results also showed a great potential for the discrimination of red nail polishes with a very similar-looking shades. Identifying the brand of the nail polish found as a trace at a crime scene, or even the exclusion of one or two brands is clearly a good choice. Thus, the infrared analysis of nail polishes can include the suspect(s) when link is established between the victim(s) or the crime scene.