Earticle

The basics of scientific verification is the reproducibility that is possible to verify the same phenomena by the third party using the given method. It is difficult to give the decisive meaning to determine guilty or not guilty when the effort to make the significant meaning from the small basis with the shortage of available evidences does not reach the basic requirements of scientific verification. In this paper, we considered the deficient part of scientific verification process that could not play crucial role in spite of many efforts and the positive considerations of justice department. We considered the admissibility of evidence and probative power of bloodstain pattern analysis in the homicide case of an old woman who died from the head injuries. The bloodstain of 4㎜ in diameter found in the inner side of a suspect’s left running shoe was inferred to an impact spatter and inferred that the bloodstain was created when a blood source in the victim’s head was broken up at a source by the suspect’s strike according to the bill of indictment and the report of bloodstain pattern analysis submitted to the court. The justice department, however, ruled the defendant not guilty because of the reason that it is difficult that the report of bloodstain pattern analysis proves the suspect guilty to the extent that ‘the judiciary exclude the reasonable doubt’. There are specific morphological proof, objective proof about the deposition time of bloodstains and the environment of deposition of the impact spatter in the condition of the analysis to the extent that the reasonable doubt was excluded in the bloodstain pattern analysis. But it seemed to have many difficulties in deciding as one. One of the objectivity guarantee or the basic notion of science is the problem that the third party can prove or approve specific facts by the same method or the same point of view. The morphological analysis such as bloodstain pattern analysis requires the proof of appropriateness about all variables generalizing the analysis that fits the objective facts, not the expert’s assertion. We wish the use of evidences of bloodstain pattern analysis takes a step forward with the considerations of this paper in the court that deals with similar cases.

Since driving under the influence of drugs(DUID) is just as dangerous as drink-driving, many countries regulate DUID by law. However risk perception of Korean people for drugged driving is still poor, the law against using drugs while driving is not established yet in detail. Oral fluid is non-invasive and easyto- use, and there is the good correlation between oral fluid and blood levels, the use of oral fluid as specimen for drug testing in DUID is available worldwide. In this study drug analysis in oral fluids and its application for drug testing in DUID were investigated. Drug lists which should be tested and various factors to be considered in oral fluid testing were researched. As the results, even though the drug lists prohibited in DUID were somewhat different in countries, the controlled drugs(legal and illegal drugs) were included in common for their lists. For methamphetamine and cannabis are most abused drugs in Korea, these drugs should be included firstly, and opiates, cocaine, benzodiazepines must to include to the DUID drug lists. Besides of controlled drugs, antihistamines and antidepressants as non-controlled drugs need to include to the lists. When oral fluid testing is applied to DUID, various factors have to be considered, i.e. specimen collection, specimen stability, chain of custody, scientific reliability, interpretation of test results and assessing likelihood of impairment. Laboratories have to establish analytical methods for drugs related to DUID in oral fluids and all methods should be validated with proper parameters to assure accuracy and reliability.

This study introduces a computer-aided simulation automation and optimization approach using ISIGHT and MADYMO simultaneously. A MADYMO model that reconstructed a specific car-to- pedestrian accident case was chosen. At first, the impact velocity of car was calculated from the principle of the conservation of energy. MADYMO simulation was also performed to verify the final position of the pedestrian. Simulation automation process was constructed using ISIGHT and 6-input variables and 2 -output variables(objectives) were also parsed. Car impact velocity was found as the most effective factor from DOE(Design of Experiment). Finally the optimal position of the pedestrian could be achieved from optimization. ISIGHT is expected as a useful solution to save much time and to obtain more compatible outputs in the forensic engineering field.

Recently there are many people who were received compensation money from opponent driver by claiming to sustain injury in the traffic accident such as a slight contact between sideview mirrors, fenders or bumpers of two cars. In this type of accident, called “moral hazard”, spreads rapidly across the nation. This study is about the threshold for occupant injury in case that the two cars slightly contact with each other. Human body feels vibration differently at different frequencies which is unlike mechanical structures. That is reason why we could not represent the vibration as only acceleration. Because there are frequencies with uncomfort and high sensitivity for human, a weighting function is usually applied to that vibration and represent as vibration dose value(VDV) or maximum transient vibration value(MTVV). As a results of this paper, we evaluated the guideline of no injury threshold in very slight contact traffic accidents.DOE(Design of Experiment). Finally the optimal position of the pedestrian could be achieved from optimization. ISIGHT is expected as a useful solution to save much time and to obtain more compatible outputs in the forensic engineering field.

The typing of short tandem repeats (STR) is the most representative method for individual identification and paternity testing in the forensic field. Although STR-based typing performs well, its limitations (relatively high amplicon size, artifacts, mutation rates) have been well documented. The forensic community has recently focused on alternative and supplementary genetic markers: single nucleotide polymorphisms (SNP), insertion-deletion polymorphisms (INDEL), and mini-STR. SNP can be captured in smaller amplicons than STR and their mutation rates are orders of magnitude lower than that of STR. To date, complex approaches which are unwieldy and often not quantitative, have been sought. INDEL are widely distributed throughout the genome and have advantages in amplicon size, artifacts, and mutation rate in comparison with STR. Besides the analysis method of INDEL is based on size like STR and so can be readily analyzed using capillary electrophoresis. In spite of the indisputable advantages of INDEL, its application in routine forensic work remains rare. Several studies on INDEL have recently been published, and interest in this area has grown since the development of commercial kits. We recently reported polymorphisms of 30 INDEL markers using Investigator DIPplex kit in 373 unrelated Korean individuals and analyzed forensic efficiency parameters in order to evaluate forensic application of INDEL in the Korean population. Further, here we report the applicability of INDEL for low copy number samples (LCN) and kinship analysis. It seems that INDEL markers will be a supplementary tool for LCN samples and kinship analysis.

Next generation sequencing (NGS) has been carried out for a number of purposes in medicine, anthropology, population and forensic genetics. It can produce massive sequencing data, and is expected to become and alternative or an additional approach to overcome the limitation of capillary electrophoresis(CE)- based forensic STR typing, especially in the analyses of mixed samples. However, there has been no available multiplex PCR system that is optimized for NGS analysis of STRs. In this regard, we constructed a multiplex PCR system for NGS analysis STRs, which composed of 4 markers of commonly used commercial kits(vWA, D7S820, D21S11 and D8S1179). Amplicons were designed to have a size ranging about 200 bp which is compatible with the read length of currently available NGS platforms. To validated the multiplex PCR system, PCR products were generated from single-source samples and the mixed DNA samples in a varying ratios, and subsequent barcodeed library was prepared and sequenced on a benchtop sequencer, GS Junior Sequencer(Roche). STR typing results obtained from NGS analysis were consistent with those from CE-based analyses both for single-source samples and mixed samples. As a result, STR types are not easy to distinguish major and minor contributor in mixed DNA samples. In contrast, NGS sequencing was able to differentiate among them by DNA sequence variation. This results suggest that NGS can be one of the good method to indicate who is the contributor in mixed DNA which was originated from crime scene evidence. In addition, we examined DNA sequence of 6 microvariants in D21S11 locus using NGS to find out particular character of D21S21 microvariants. They showed mutations and sequence variations in the repeat region of D21S11 short tandem repeat (STR) loci.

Ethylene glycol is frequently used chemicals in the coolant of internal combustion engines which is essential for the proper function of the engine. In this study, the analysis by GC/MS was adopted through ketalization and esterification of ethylene glycol in the oil with cyclohexanone and phenylboronic acid to check out whether the lubricant oil was polluted by the chemical in the coolant. Acetonitrile was used as extracting solvent and the detection limit for ethylene glycol in acetonitrile solvent was less than 0.1 g/g. The linearity of the calibration curves plotted by the characteristic ions of m/z 99 and m/z 148 for the reaction of ethylene glycol with cyclohexanone and phenylboronic acid against the ions of m/z 103 and m/z 152 which are the characteristic derivatized ions of deuterium substituted ethylene glycol shows good linearity of r2 values of 0.9926 and 0.9986 in the concentration range of 10 g/g . 1,000 g/g. The recovery was about 72 % for both derivatization methods for the oil containing 1,000 g/g of ethylene glycol. Especially, the method by using was relatively easy in the derivatization because the heating was not necessary.

Sampling biological evidence is one of the most critical step in forensic DNA typing. Touch DNA samples were known to be difficult to analyse compared to bloodstain, semen stain and saliva stains. In this study, nano filament fiber was evaluated as a tool for collecting trace DNA samples by comparing other commercial swabs such as cotton swab, cotton gauze, flocked swab, isohelix swab. Diluted blood stains were prepared on porous and non-porous materials such as wood and glass plate, respectively. DNA quantity was analyzed by qPCR and compared. Nano filament fiber showed higher concentration of DNA compared to other tools such as cotton swab. This study showed the feasibility of nano filament fiber as a novel tool for trace DNA analysis.

Carbon monoxide is colorless, odorless gas generated when carbonic fuel attains an incomplete combustion. As carbon monoxide is slightly lighter than air, and 200 - 250 times stronger than oxygen in affinity of hemoglobin, when carbon monoxide is inhaled, this can cause carbon monoxide poisoning as it is easily combined with hemoglobin in blood, and the oxygen transport ability of blood is lost, which leads to a situation of suffocation. An accident took place that involved the death of two divers who wore air containers compressed by using air compressors, and dove into the sea to harvest sea cucumber. In about 10minutes after they started harvesting, they came out to, collapsed on the land, and died. The compressed air they used at that time was very fatal as carbon monoxide accounted for 0.10- 0.25 % of the compressed air. The actual straight distance of the air inlet of air compressor was about 80 cm away from an outlet of exhaust gas, which was very close between inlet and outlet. This indicates that the air compressor was in a structurally deficient state in that some exhaust gas can be inhaled through the inlet as the height of the inlet was the same as that of the outlet. This study herein investigated the chance of containing carbon monoxide in case that air is compressed by air compressor. The air compressor was connected with rubber belt and motor, internal combustion engine that obtains energy by burning gasoline, and carbon monoxide accounted for 0.6 - 1.3 % of exhaust gas of the motor. Carbon monoxide was not detected in the air compressed in a windless condition; whereas carbon monoxide was detected as exhaust gas was intruded through an air inlet due to the effect of wind, and the content of carbon monoxide increased by 0.05 % or above. Furthermore, the content of carbon monoxide increased by 0.25 % or above after about 20 minutes when the air compressor was used indoor, not outdoor, which is a very dangerous situation. Therefore, for safe air compression, an exhaust pipe should be installed so that exhaust gas cannot be intruded into air inlet, and air compression should be conducted outdoor as indoor air compression puts even a person who compresses air into danger. By dong this, accidents can be prevented.

The bodily wound like whiplash injury(neck injury) and sprain of lumbar spine may occur in a rear-end collision accident. The medical certificates about slight injury have been published in low- speed rear impact traffic accident. The truth or falsehood of them has been social issues all over the world. NFS in Korea have made an assessment of faked illness since 2008 with the application of MADYMO simulation program. Generally NFS's appraisal statement come to a conclusion that there is very little likelihood of driver & passenger's remarkable motion change and injury as a result of it in low-speed rear impact traffic accident. The medical certificate is in competition with appraisal statement in the area of civil and criminal suit. The both of them have admissibility of evidence but are rival relation in probative force. The rear-end collision accident result in physical change of impacted vehicle and its driver and passenger. The force, impulse, energy and speed change(ΔV, Delta-V) are used as a physical quantity for estimating their motion change extent and level. The speed change is defined as the variation of speed in before and after rear-end collision. It can be calculated by vehicle's weight ratio and relative speed difference theoretically or measured in collision test. Also it is useful as an indicator for estimating the motion change extent and level. We suggest that critical speed change(ΔVc) be 10.15km/h on the basis of several papers and documents. We review 3 collision tests previously performed by outside institution. We cannot expect the remarkable motion change of impacted vehicle in speed change less than 10.15km/h. Finally, we propose a procedure model for evaluating motion change of vehicle and driver & passenger's injury in low-speed rear impact and similar traffic accident. It is composed as follows : 1. Classifying low-speed rear impact or similar traffic accident, 2. Calculating speed change(ΔV) quantitatively or Estmating speed change on the basis of damage of impacted vehicle, 3. Comparing ΔV with ΔVc, 4. Deciding the possibility of injury. There are 5 levels in damage of impacted vehicle as follows : ①Slight ②Moderate ③Severe ④Extreme ⑤Total. There are 5 steps in motion change of impacted vehicle and its driver and passenger as follows : ①Bare ②Very slight ③Slight ④Remarkable ⑤Very remarkable. There are 5 levels in the possibility of injury as follows : ①No risk ②Spontaneous cure ③Outpatient treatment ④Short cure below 30 days ⑤Long cure above 30 days.

In this study, we used immunoassay for the preliminary test to detect methamphetamine, cannabinoids and their metabolites in human urine. Specifically, we compared four different immunoassays: FPIA (Fluorescent Polarization ImmunoAssay), EMIT (Enzyme-Multiplied Immunoassay Technique), CEDIA (Cloned Enzyme Donor ImmunoAssay) and KIMS (Kinetic Interaction of Microparticles in Solution). We evaluated the performance of immunoassays using common parameters: true positive, true negative, false positive and false negative. Sensitivity, specificity, accuracy and false positive/negative rates were also calculated. The findings from this study indicated that FPIA, EMIT, CEDIA and KIMS can provide acceptable preliminary results to detect methamphetamine, cannabinoids and their metabolites in forensic toxicology.

An accident happened which a laborer burned himself in the toilet in the office building of the factory using CNC(Computer Numerical Control) gas cutting machine because of an unknown fire and he was dead a few days later. Immediately after the fire, colleagues asked him all the details and the deceased stated that when he sat on a cistern type flushing toilet and lighted a cigarette with a lighter, the fire happened with a sound like "pung". In the result of the initial investigation of the police the fire causes were not found and the police requested the National Institute of Scientific Investigation to make a close investigation of the fire. In the results of the field investigation and the reappearance experiments, we concluded the fire cause the following statements. One day before the accident by the unlocking of the backflow-preventing valve in the process of blow of cooling water by inserting high pressure oxygen gas in the cooling water pipe to prevent a winter- breaking of the cooling water pipe used in CNC gas cutting machine along the water supply pipe, oxygen outflowed through the cistern in the flushing toilet about 50m apart from the gas cutting machine and stayed in the toilet. The next day morning at the moment that the deceased goes in the toilet and lights a cigarette with a lighter, rapid flame was generated with an explosive sound like a gas explosion because of the high dense oxygen.

There was an explosion at a core-drying oven in a foundry and a worker was dead. A core is used to cast something which needs empty space in it. A core-drying oven is an apparatus to dry a core which is spreaded by mould wash. Through scene investigation and examination for finding components, we find that the cause of the explosion is that 2-ethylhexanol, which is one component of mould wash, reach the specific condition. To prevent similar accidents, we urge that the risk criteria for mould wash should be provided as soon as possible.

The settlement of who drived a car precedes the others of the process in investigating traffic accidents. These days it is more difficult than before to decide a driver, since an accident-causing driver, an offender, should have corresponding criminal and civil liabilities and thus the offender may hide a matter of fact. When, in particular, one or more of passengers died in an accident, the matter of who drived a car may be controversial. We offered the suggestion that one of direct evidences, the fiber compression on, for instance, dashboards or instrument panels in front of seats inside a car should be used in order to discriminate a driver. The fiber compression on panels can be used to confirm locations of each passenger, since the body tends to impact against surroundings caused by the law of inertia at the very moment of accident and thus the clothes, usually pants, of passengers can be compressed. In the last study, ‘the study of discriminating a driver in traffic accident( )’ in 2001, we experimently saw the characteristics of fiber transference from clothes to instrument panels by impacting a steel ball wrapped up in a piece of cloth against a panel. We saw various aspects of the fiber compressions, qualitatively and quantitatively, according to a variety of fibers and incidence angles on panels. We confirmed that it is easier to be compressed on panels when fabrics, made of the cotton or the wool among kinds of the fiber, impact on a panel and by a certain degree of an incidence angle. Since then, we actively have been using the fiber compression on panels inside a car in order to discriminate a driver in practical questions. This study shows diverse aspects of fiber compressions and its usefulness in practical cases in a period of ten years, between 2002 to 2011. We strongly recommend that the fiber compression should be detected with precision in a careful manner and then actively utilized.

Human mitochondrial DNA analysis from canine feces was handled in this work. One woman committed suicide by hanging herself on door knob in her studio apartment. A part of her face skin was eaten by someone or something. Because of this case, ghostly rumors over a cannibal killer had been spread in the local society. But, it was estimated that her pet dog, Chihuahua, was referred to her broken face. The establishment of existence of human material in two lumps of canine dung and the identity test of this material with the dead were requested by the police. We used Micro Kit and Inhibit EX tablet in QIAamp DNA Stool Mini Kit for DNA purification. The DNAs were isolated from swabs rubbed lightly the exterior surface of dried canine feces, from hairs imbedded in dung, and from presumptive tissues that showed positive bloodstain test (leucomalachite green). Using direct sequencing analysis, the canine and human mitochondrial D-loop region could be acquired accurately from swabs and human D-loop region could be acquired from hairs imbedded in one lump of dung. The human D-loop region from swabs and hairs was identical to that from the blood of the deceased. Analysis result from presumptive tissues was not good but had partly identical haplotypes with the dead. D-loop region located in the human mitochondrial DNA was successfully acquired from canine feces. We could not get the dead woman’s short tandem repeat (STR) profile from canine feces. This is the first case report which detects human mitochondrial DNA from canine feces.