Earticle

This study was conducted to understand alcohol kinetics for Koreans and to present reasonable parameters for the application of the Widmark equation. A total of 44 healthy adults(11 female and 33 male) was selected and assigned to drink 1 g of ethanol per kg body weight of individual within 1 hour. Blood samples were then collected every 15 min for the first 3 h, 30 min next 3 h, and 1 h last 9 h. All samples were analyzed by gas chromatography with a flame ionization detector(GC-FID) for blood alcohol concentration(BAC). The maximum BAC(Cmax) was 0.145 ± 0.028%(g/100 mL) in average under the controlled experimental condition. Alcohol elimination rates(β-slope) in average were 0.0185 ± 0.0025 %/h for male and 0.0211 ± 0.0025 %/h for female, respectively. Widmark’s factor(rho-factor, r) in average were 0.61 ± 0.060 L/kg for male and 0.56 ± 0.073 L/kg for female. The Widmark alcohol calculation for Koreans is suggested that 1) It cannot be argued about the absorption rate due to the diversity of drinking types 2) The rapid absorption phase is an average of 15 minutes after drinking and there is no significant change in the first 1 hour 3) If the BAC is less than 0.02% or within 90 minutes of the end of drinking, the back-calculation is not possible 4) Estimation of alcohol concentration should be calculated as decreasing from the start time of drinking 5) The elimination rate is 0.0192 ± 0.0027 %/h for drinking driver 6) Widmark's factor should be calculated individually based on height, weight, sex and age.

Component analysis of pigments is very important in terms of forensic art or restoration of artworks and cultural properties. In this study, the components were analyzed by non-destructive analysis methods such as spectrophotometry, X-ray fluorescence(XRF) spectroscopy, X-ray diffraction(XRD) spectroscopy and Raman spectroscopy for 37 types of natural pigments(Natural Seokchae). The analysis found that there were some color differences depending on the type of main coloring mineral, the degree of other mineral content and the stoichiometric compositions. As a result, the constituent elements of the Natural Seokchae were determined by XRF. The coloring minerals such as azurite and lazurite(blue), malachite and celadonite(green), cinnabar and realgar(red), orpiment(yellow), goethite and hematite(brown), calcite(white), ilmenite(black), and clinochlore(gray) were determined by XRD. Raman spectra were obtained from 30 out of 37 samples; specific peaks of azurite, lazurite, malachite, cinnabar, realgar, calcite, albite, quartz and goethite were identified according to their corresponding pigments.

The crackdown on the drunk driving is continuously enforced and the drivers might not agree with the result of the blood alcohol test results. Especially the test result could be controversial for the blood sampled by using disinfection ethanol swab, without using the sterile liquid at the blood sampling kit. In this study, the effect of the disinfection ethanol swab on the concentration when sampled by syringe under ethanol remaining condition through SPME-GC/MS analysis with the internal standard of isotope substituted ethanol(CD3CD2OH). The sample taken through the dried pig skin didn’t show meaningful value of ethanol but the result of ethanol residual case showed the ethanol concentration from the value of quantification limit ∼ 0.003% with the average value of about 0.001%. The quantification limit of this method was about 0.0005% and the linearity of the calibration curve showed the r2 of 0.9999 or more which was plotted by the area response ratio between the ion of m/z 45 for ethanol and m/z 49 for internal standard.

Gasoline is highly flammable substance which also shows chronic toxicity when inhaled. Accidental poisoning cases caused by hydrocarbon fuel occur continuously in modern times, therefore the demand of standardized method and threshold in gasoline poisoning cases are increasing in the forensic science field. In this study, analysis conditions and results for the detection of each components in gasoline from fatal poisoning case using solid-phase microextraction and solvent extraction are presented. Specific composition distribution patterns of autopsy samples and field samples are estimated from detection rate and score of each components. From field samples, higher alkanes were mainly found, while autopsy samples had lower alkanes which have relatively high penetrating ratio into body. Besides, aromatic compounds showed relatively high loss rate in both samples, because of their high volatility.

Many DNA samples are exposed to various environments at crime scenes and mixed with other substances that adversely affect STR profiling. In this study, DNA quantification and STR profiling were performed up to 40 weeks with body wash or hand sanitizer mixed with saliva, blood, and semen at a final concentration of 1%. In addition, serological preliminary tests such as SALIgAE, LMG, and AP and immunological confirmatory tests using RSID kits were conducted to examine the effect of body wash and hand sanitizer on three body fluids. Body wash containing surfactants showed more serious effect on DNA quantity and STR quality than hand sanitizer containing ethanol. Saliva was immediately decomposed after mixing hygiene products, making it impossible to analyze STR, however blood and semen produced full STR profiles after 40 weeks of mixing. As a result, saliva was very vulnerable to hygiene products, but blood and semen were not affected until 40 weeks after mixing. In addition, the discrepancy between serological test and STR profiling in blood and semen samples showed that STR analysis should be performed even if the serological test was negative.

New synthetic drugs, coined by the United Nations Office on Drugs and Crime(UNODC) as New Psychoactive Substances(NPS), have become a new threat worldwide. The NPS is dangerous not only because their safety has not been tested but also because it can be a threat to public health and security. Among the new drugs, phenethylamines(PEAs), which are mostly central nervous system stimulants became drugs of concern worldwide especially in Asia and the United State. In order to develop a rapid method for detection of PEAs in biological fluids, especially in whole blood, gas chromatography-mass spectrometry(GC-MS) using Dried Blood Spot was attempted. DBS is a sampling and extraction method and has been used in many fields, because it is a less invasive sampling method in which blood is taken by stabbing a finger instead of venous blood. Nine PEAs of 5-MAPB, 5-APDB, 5-EAPB, DMMA, 2C-C, 5-IT, PMMA, 25C-NBOMe, 25D-NBOMe were targeted and spiked into whole blood. Selectivity, carry-over, detection limit, linearity, precision, recovery, matrix effect, drying time, extraction solvent, and analyte stability were studied with these nine PEAs. As a result, all nine were well detected under this condition. Nine PEAs showed good linearity with an r-squared value of 0.99 or higher. Stability test showed all of them were stable for up to 30 days at the room temperature, 4 ℃ and –20 ℃ under the range of 2, 10, 20 mg/L. The DBS extraction of nine PEAs in blood proved to be fast, easy to transport and store samples. This is the first study to detect nine PEAs in blood using the DBS extraction method.

Crime scene investigator sought to assist in efficient identification by proposing an identification checklist when they found a toolmark at the crime scene. The checklist currently in use by the national police agency has a checklist of the dead body and the checklist for toolmark is insufficient. Since korea’s judicial environment is turning into a court oriented trial securing admissibility of evidence in the field of scientific investigation is important. Therefore when the crime scene identification it needs to be verified objectively. it is believed that a toolmark identification checklist is necessary because it must be considered that the collected evidence must comply with the chain of custody so that it can have evidence capability in court.

The time information recorded in a vehicle black box or CCTV is displayed in the text time(ex: YYYY/MM/DD hh:mm:ss). However, when restoring images from inactive areas, temporary files, or damaged video files, there could be a problem that the sequence of images restored to frame units is not arranged in that of the actual recorded time. To resolve this issue, we recognize time information recorded in text format at the top or bottom of the image, and rename the image file via the recognized time information. At that time, images that have been renamed and sorted chronologically can be made into continuous videos. In this paper, Optical Character Recognition(OCR) was used to recognize time information. OCR-related research has continued for a long time and has recently been available through many open sources. Thus, time information of the image is extracted by applying Convolutional Recurrent Neural Network(CRNN) based OCR, Tesseract OCR, and EasyOCR. The expression of time information in vehicle black boxes and CCTV is expressed in various ways(ex: text font, background and text size). The performance of each OCR was compared and analyzed through test images of time information presented in various forms. It was shown from the comparative analysis that the CRNN-based method has the highest recognition performance among OCRs used in the experiment. Moreover, it was confirmed that a prediction rate is approximately 5 times faster for predicting a single image.

According to the recent press release from the Financial Supervisory Service, automobile insurance fraud is increasing every year. The government tried to respond to insurance fraud by enforcing the Special Act on Prevention of Insurance Fraud. However, the size of insurance fraud is increasing due to intelligent and organized insurance scammers. In order to respond to insurance fraud, the vehicle driving information prior to a collision must be objectively verified by the vehicle accident analyst. EDR is one of the functions of ACU to record the event data when crash occurred. EDR data should be verified whether the data is recorded from the specified situation by using PDOF result, airbag deployment status and ignition cycle. In this study, one of the vehicle insurance fraud case was covered. In that accident case, the driver claimed that the vehicle could not be operated due to out of control. In the EDR data, the driver did not manipulate the vehicle event data though it was in a dangerous situation. So, when the EDR data was recorded and could be download from a damaged vehicle, the driver's operation information can be verified.

In a traffic accident, scientific data are needed to refute the driver's false claim or statement that the shock was not recognized at the time of the accident. ISO2631 deals with methods and evaluation criteria for measuring human vibration of vehicle occupants. In this study, we tried to find out the characteristics of human body vibration transmitted to vehicle occupants on comfort. In evaluating the impact of unpaved roads or speed bumps on vehicle drivers in future traffic accident site investigation, it is expected that objective evaluation can be performed by utilizing the human vibration measurement method, evaluation criteria, and experimental values performed in this study.

Asphyxia typically occurs due to oxygen deficiency in confined spaces. A male researcher died in a minor car accident. He had loaded a container filled with liquid nitrogen in his car the day before the accident. Clinical analysis of blood showed that blood alcohol concentration(BAC), carboxyhemoglobin (CO-Hb), drugs and toxins were negative. During the car investigation, it was found that there was frost around the lid of the liquid nitrogen container with a trace amount of liquid nitrogen left. To determine the cause of death, the simulation test was performed by reconstructing the situation of liquid nitrogen leaking in a confined space. The results showed that liquid nitrogen in the container was continuously evaporated and reduced the oxygen concentration in the car. After 20 min the state of oxygen deficiency was reached and then the oxygen concentration was cut down to 6.5 % within 10 hours. It was concluded that the cause of death was oxygen-deficient circumstance resulted from the evaporation of liquid nitrogen in the car. In order to determine the cause of death, it is necessary to perform a simulation test considering all potential factors that may affect the accident.

Fluoride and its inorganic salts are widely used in industry for various purpose such as etching, metal cleaning, rust removing, etc. Fluoride ion is easily absorbed in the gastrointestinal tract after ingestion. Once fluoride has been absorbed, it interferes with metabolism and enzyme mechanisms. As a result, dysrhythmia associated with electrolyte alteration causes cardiovascular compromise, arrest and death. Herein, we report a case of fatal intoxication involving fluoride. A 67-year-old man was found groaning by his wife after drinking some unknown liquid. He was transported to a hospital emergency room and died after 90 min. General toxicological screening of the autopsy biological samples and the liquid at the scene could not reveal the presence of any toxic substance. However, analytical results by ion chromatography showed that the aqueous solution contained fluoride and ammonium ion. Thus, the quantification of fluoride was carried out in the autopsy specimens and the fluoride concentration were 61.5, 28.4 and 5,000 mg/L in heart blood, peripheral blood and gastric contents, respectively. Based on these toxicological results and autopsy findings, the cause of death was determined to be acute fatal intoxication by ingestion of the solution containing fluoride. This is the first report of the fatal case of fluoride poisoning in Korea.