Complete and clear DNA profiles are the decisive evidence for criminal suspects to be identified. Whereas, in forensic practice, DNA profiles come out at times as mixed or partial ones, resulting in the relevant cases turning into “cold cases” because of chronic postponement out of inability to compare and match. The Express Search of National Database can offer crucial support for solving this sort of cases if the relevant partial DNA spectrums from one “cold case” become available. Based on this idea, 21 unsolved cases in the year of 2011 were assorted in combination of National Database by the mixed DNA profiles being de-convolved into individual spectrums to make the potential suspects’ able to be matched. This handling conduced 19 cases having got their valuable DNA spectrums, successfully directing two murder cases to be solved by the above method of de-convolution. How to produce an available DNA profile and split out its usable spectrums is the key to solve the cases of mixed evidential materials without suspects attached. Consequently, the optimization of amplification parameters and conditions, selection of reliable loci to be matched and ascertainment of multiple chosen collocations were analyzed and discussed in this paper, therefore putting forth the essentially technical points on de-convolving a mixed DNA profile. This paper presents the deep mining of partial DNA profiles to exert their potential values with National Database to play its predominance of data and information, bringing the dormant partial DNA spectrums into life and “cold cases”uncovered, very beneficial to supply thoughts and reference for setting up new patterns of cases solving.%清晰的 DNA 图谱对于认定犯罪嫌疑人具有决定性的证据作用。然而在实际检验中，经常得到不完整DNA 图谱或混合图谱，相关案件因无法查询比对而长期搁置成为“冷案”。本文从这一难题出发，结合混合样品人工拆分和“全国公安机关 DNA 数据库快速协查平台”，对2011年的未破积案进行梳理，为21起未破案件中的19起查拆分出有价值的 DNA 分型，并成功告破两起命案。通过深度挖掘不完整 STR 分型的潜在利用价值，大大提高了“休眠”DNA 信息的使用效率，为形成破案模式的新常态提供了思路和借鉴。
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