Earticle

This study assesses and compares flammable and unique chemicals in the pesticide, air freshener/deodorizer, tire polishes, hair sprays, sun blocks, anddeodorants. Solvents in the group of pesticide, air freshener/deodorizer, hair spray and deodorant were classified according to butane, propane, alkane(C11- C14), or ethyl alcohol. In specifically, phthalthrin and phenothrin were detected in pesticide product. Moreover, air freshener/deodorizer was mainly verified by masking effect and hair sprays,sunblocks, and deodorants was mainly found in scent of cosmetics. As results, it might be possible to classify the types of aerosol products based on chemical components found in these products. Therefore, this approach can be used for analysis of fire debris related to arson or explosion cases.

In cases of sexual assault, the transfer of biological fluids between the assailant and victim provides investigators with valuable evidence of physical contact between the suspect and victim. However, with increasing public awareness of the identifying properties that their high evidential value, particularly that of DNA, sexual assailants may seek to avoid such transfers and render the evidence inaccessible. No matter how, the use of a condom lubricating substance produces its own associated trace evidence, and the detection and identification of such residues can provide valuable intelligence information as well as potential forensic evidence in court. In general, the silicone-based lubricants are the most commonly encountered lubricant on condoms. The detection of silicon oils in swab evidence smeared the victim’s vagina allows the possibility of being sexually harassed with the use of a condom. In this study, the new technique for analysis of condom lubricants without any solvent extraction was carried out using EGA-MS and MS-GC/MS, and the results were compared with that from the conventional method. According to the EGA-thermogram pattern, MSGC/ MS was applied to the sample and more simple chromatograms than ones using Py-GC/MS could be obtained as volatile compounds and pyrolyzed products could be analyzed separately. The results of this work demonstrated that the presence of condom lubricants in forensic evidence could be simply screened by EGA-MS without any solvent extraction. MS-GC/MS results also supplied the detailed information not only for the silicone oils and other additives but also for the condom rubber materials, which could not be easily approached by other conventional methods.

In the case of spattered blood in bloodstain pattern analysis, the impact angle can be calculated by looking at the shape and size of it. The impact angle is a constant angle that occurs when the blood droplet touches the target surface, and the formula sin = W / L is used to calculate the impact angle. This formula is now used in the analysis of bloodstain patterns, and the results show that the error rate is about 18 % depending on the conditions. Nevertheless, since there is no formula to reduce the error rate, a new modification formula is being studied. In this study, the optimum impact angle calculation formula is derived from the wall surface where many scattered blood is found in crime scene in Korea and the error rate of the other impact angle calculation formula is compared. Currently, the use of wallpaper in Korea has a tendency to increase rapidly in silk wallpaper. However, the most cheap and easy-to-install wallpaper, which is still used the largest percentage, has been used as the target surface. Experimental results on the optimal angle of impact angle along the surface revealed that the optimal formulas were different for each surface and the -12 to 0 % error rate was observed when the optimal formula for one surface was applied to the other surface. Therefore, the optimal angle of impact angle should be applied differently depending on the surface, and accordingly, a database of optimal formulas for each surface is required. In the case of the laminated wallpaper, when the experimental condition for obtaining the optimized formula is not available, the improvement formula W / L = 0.9145 sin (0.02619? + 0.6478) + 0.5629 sin (0.04441? + 3.9020) will contribute to solve the case by deducing the correct impact angle value from the existing formula.

Bloodstain Pattern Analysis is a technique used to reconstruct crime scenes. There are various patterns of blood strewn around the crime scenes, and bloody parts without protrusions can be used to estimate a Area of Origin by calculating the impact angle by mathematical formula. However, the formula currently used is a linear method that produces errors by various variables. Therefore, it differs from the actual impact angle. To overcome this, a formula for difference in surface has been studied in previous studies. However, this formula also can differed with the results depending on its height, so the study drew a more calibrated formula taking into consideration the differences in height among various variables. Experiments were carried out at intervals of 10° from 20° to 70° at intervals of 20cm from 20cm to 100cm in height, but 20cm and 40cm were excluded because they showed no tendency. As a result It has been concluded that the formula for the height is different for each height, so we have to decide what is the most optimal formula and what to experiment further. The most optimal formula was concluded provisionally is W/L=0.9048 sin(0.02683?-0.1974)+0.1172 sin(0.06951?+1.728) this equation is based on experimental data and It was chosen because the error rate was the lowest among the derived formulas. Based on this study, experiments required later will be different collision angles depending on the speed.

The current research focuses on identifying chemical reagents that can be used to detect latent fingerprints on stainless steels in submerged aquatic environment which can damage the quality of the fingerprints. Fingerprint data has been collected from the limited environment and we used a scoring system to identify chemical reagents that can preserve the quality of the fingerprints as well as prolong the detection period. As a result, we used a collection of chemical reagents that can be used on wet surface and found the detection rate is significantly diminished after 3 days of water exposure. However, within 3 days of exposure we were still able to identify the fingerprints with the reagents. Interestingly, SPR and Errosoferric Oxide, which are commonly used on wet surface, was not effective in our study and the reagent CA that is normally used on non-porous surface also was not effective and had the lowest detection score. Nile Red and ORO regents however had outstanding detection scores in comparison with other reagents. This research can be further used to identify latent fingerprints on stainless steels in aquatic seawater.

Nicotine is a major component of tobacco and the addictive substance in cigarette smoke. Wide use of e-cigarette has been leading acute intoxication of nicotine in recent days in Korea. In this study, acute nicotine and antihistamines intoxications in two suicidal cases are reported. A male and a female were found dead in a hotel. Near the victims, two disposable syringes filled with about 5 mL of brown liquid and two empty e-cigarette liquid bottles labeled with ‘HO-OOO’ pure nicotine solution were found. Several injection marks were found on the back of left hands in each person. A series of forensic autopsy specimens were collected and analyzed. Nicotine, doxylamine(DA) and Diphenhydramine(DPH) were detected in two victim’s biologic specimens. Liquid chromatography/Tandem mass spectrometry(LC/MS/MS) was used for identification and quantification of the detected drugs. Femoral venous blood, heart blood, bile, urine, cerebrospinal fluid, gastric contents and tissue at the injection site were collected and analyzed for drug testing. The concentrations of nicotine in femoral blood in male and female victim were 4.85 mg/L and 0.60 mg/L, respectively. The concentrations of DA were 1.48 mg/L and 0.84 mg/L, and the concentrations of DPH were 1.06 mg/L and 0.16 mg/L in femoral blood in male and female victim, respectively. Based on these results, we determined the cause of death in these suicidal cases could be multidrug poisoning involving nicotine, DA and DPH.

This case report handled the comparative sequence analyses of plastid DNA markers acquired rom botanical stains of a suspect’s clothes and a sickle which were the items of criminal evidence in agricultural property damage case. Three victims found out that their cherry tomatoes in green houses of the width of about 5,950 square meters were cut off. For the forensic botanical analysis, the police requested a suspect’s clothes, cotton gloves, two sickles, gauzes and cotton swabs collected by wiping a suspect's motorcycle and car. Cherry tomato plants from victims’ green houses as positive controls were received. The nucleotide sequences of plastid trnL-trnF IGS and psbA-trnH IGS regions from evidences were compared with positive controls and with DNA databases in GenBank of National Center for Biotechnology Information (NCBI). According to nucleotide sequence results, the lower part of suspect’s training wear got stained with tomato substances, the upper part with kiwifruit. The wooden handle of a sickle of a suspect showed the apricot nucleotide sequences. Gauzes, cotton swabs, two gloves, two pants and other sickle showed no results by plastid DNA markers. Plant stains from clothes and wooden materials or wood itself can be genetically analyzed for the elucidation of criminal cases.

We analyzed 838 cigarette butts discovered amongst the seditious propaganda in South Korea. The seditious propagandas are consistently distributed from North Korea to South Korea and most of the found cigarette butts were currently circulated only in North Korea. It suggests that these cigarette butts are presumed to be smoked by North Korean. Through the autosomal STR analysis for 15 autosomal short tandem repeat loci and 1 sex determination locus using AmpFLSTR Identifiler Plus PCR Amplification kit, 123 profiles were confirmed. For all 15 STR markers, observed heterozygosity ranged from 0.642 to 0.894 and gene diversity ranged from 0.6016 to 0.8721. The accuracy probability according to the Hardy-Weinberg law showed from 0.091 to 0.921. This study shows the first investigation of the allele frequencies and statistical parameters for autosomal STR profiles of a population assumed to consist of the North Koreans.