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영어

In Korea, by imposing on ‘Acts on the protection and use of DNA identifying information’ from 2010, DNA profiles obtained from convicted offenders and crime scene evidence have been stored and managed at National forensic DNA database. This makes it possible to compare the unknown DNA profile from crime scene evidence to DNA profiles from convicted offenders in national forensic DNA database. If DNA profiles are matched, the crime cases will be solved by catching criminals. Therefore, confirming DNA profiles from crime scene evidence in DNA database to find match DNA profiles is one of the good ways reducing lots of time and money in order to solve crime cases. In this study, 5681 samples of theft scene removing such as murder, sexual assault, robbery were analyzed and classified into five parts which were 277 samples containing blood stain (4.9 %), 1998 samples containing saliva stain (35.2 %), 45 samples containing semen stain (0.8 %), 241 samples derived from human tissue (4.2 %), and 3120 touch samples (54.9 %). Interestingly, both saliva stain samples and touch samples were composed of about 80 percent of theft samples suggesting that two samples are important for solving theft casework. 97.5 percent of blood stain samples, 85.9 percent of saliva stain samples, 96.7 percent of semen stain samples, 56.3 percent of human-derived tissue samples, and 32.7 percent of touch samples were successfully STR typed. To know if DNA collection methods from theft samples have an effect on STR typing success, we divided 5681 samples into two groups. The first group was crime scene evidences directly collected from crime scenes, and the second group was DNA samples which was obtained from crime scene evidences using cotton swabs. Crime scene evidences account for 46.0 percent of theft samples, and DNA samples with cotton swab make up 54 percent of theft samples. On the contrary, 68.4 percent of crime scene evidences and 50.1 percent of DNA samples with cotton swab were successfully STR typed, respectively. These results suggest that development of DNA collecting method is required to increase success of STR typing. Touch samples including clothes, vehicle items, plugs and cables, stones, woods, steels, handled, or touched objects which typically containing low amounts of DNA have been more deeply investigated. Because touch samples are less exploited than other samples such as containing saliva, semen, or blood. As we expected, while touch samples showed the highest proportion among theft samples, STR typing success were the lowest among them suggesting that researches for increasing success of STR typing with touch samples are needed.