Bode Technology, Lorton, VA, USA.
Forensic Technology Center of Excellence, RTI International, Research Triangle Park, NC, USA.
J Forensic Sci. 2022 Jan;67(1):149-160. doi: 10.1111/1556-4029.14881. Epub 2021 Sep 9.
Forensic examiners must determine whether both latent fingerprint development and DNA profiling can be performed on the same area of an evidence item and, if only one is possible, which examination offers the best chance for identification. Latent fingerprints can be enhanced by targeting different components of fingerprint residues with sequential chemical treatments. This study investigated the effects of single-reagent and sequential latent fingerprint development processes on downstream DNA analysis to determine the point at which latent fingerprint development should be stopped to allow for DNA recovery. Latent fingerprints deposited on copy paper by one donor were developed using three sequential processes: 1,8-diazafluoren-9-one (DFO) → ninhydrin → physical developer (PD); 1,2-indanedione-zinc (IND-Zn) → ninhydrin → PD; and IND-Zn → ninhydrin → Oil Red O (ORO) → PD. Samples were examined after the addition of each chemical treatment. DNA was collected with cotton swabs, extracted, quantified, and amplified. DNA yields, peak heights, number of alleles obtained, and percentage of DNA profiles eligible for CODIS upload were examined. DNA profiles were obtained with varying degrees of success, depending on the number and type of treatments used for latent fingerprint development. The treatments that were found to be the least harmful to downstream DNA analysis were IND-Zn and IND-Zn/laser, and the most detrimental treatments were DFO, DFO/laser, and PD. In general, as the number of treatments increase, the opportunities for DNA loss or damage also increase, and it is preferable to use fewer treatments when developing latent fingerprints prior to downstream DNA processing.
法医检查人员必须确定是否可以在证据物品的同一区域同时进行潜在指纹开发和 DNA 分析，如果只能进行其中一种，则哪种检查提供了最佳的识别机会。潜在指纹可以通过用顺序化学处理靶向指纹残留物的不同成分来增强。本研究调查了单一试剂和顺序潜在指纹开发过程对下游 DNA 分析的影响，以确定停止潜在指纹开发以允许 DNA 回收的时间点。使用三种顺序处理方法在复印纸上开发了来自一位供体的潜在指纹：1,8-二氮杂芴-9-酮（DFO）→茚三酮→物理显影剂（PD）；1,2-茚二酮-锌（IND-Zn）→茚三酮→PD；和 IND-Zn→茚三酮→油红 O（ORO）→PD。在添加每种化学处理后检查样品。用棉签收集、提取、定量和扩增 DNA。检查 DNA 产量、峰高、获得的等位基因数量以及可用于 CODIS 上传的 DNA 谱图的百分比。根据用于开发潜在指纹的处理数量和类型，DNA 谱图的获取成功率各不相同。发现对下游 DNA 分析危害最小的处理是 IND-Zn 和 IND-Zn/激光，而最有害的处理是 DFO、DFO/激光和 PD。一般来说，随着处理次数的增加，DNA 损失或损坏的机会也会增加，因此在进行下游 DNA 处理之前，最好在开发潜在指纹时使用较少的处理。
