Archived or directly swabbed latent fingerprints as a DNA source for STR typing

Former studies [Nature (1997) 387, Electrophoresis 20 (1999) 2870, P. Van Renterghem, D. Leonard, C. De Greef, Progress in Forensic Genetics, Vol. 8, 2000, p. 501, J. Forensic Sci. 45 (3) (2000) 687] have shown that even a single skin contact, documented by a latent fingerprint, can transfer enough DNA for a genetic analysis. It was proven in these studies that it is possible to swab fingerprints from surfaces [Nature (1997) 387, Electrophoresis 20 (1999) 2870, P. Van Renterghem, D. Leonard, C. De Greef, Progress in Forensic Genetics, Vol. 8, 2000, p. 501] and use them as a DNA source. Usually, however, discovered fingerprints are removed with scotch tape and placed on evidence cards for further investigation.In this study, we tried to assess the potential use of latent fingerprints as a DNA source for STR typing. The materials (magnetic powder, soot powder and scotch tape) used for visualization and archiving fingerprints in Germany were tested for their PCR inhibitory characteristics. Then, fingerprints were placed on clean glass surfaces, visualized and tested for their usefulness as a DNA source.Obtained DNA was quantified and tested in an STR system. Partly it proved possible to type fingerprints taken directly from the surface as well as fingerprints removed from the surface with scotch tape.     

掺杂Cd的水溶性荧光ZnSe/MPA量子点显现胶带手印方法

目的探索水溶性荧光量子点溶液——掺杂镉的硒化锌（ZnxCd（1-x）Se）对胶带手印的显现方法。方法以巯基丙酸（MPA）为修饰剂合成了掺杂Cd的水溶性荧光ZnSe/MPA量子点,利用它显现水浸胶带及粘连胶带上的油汗指印,并在365nm下拍照成像。结果良好的显现出水浸胶带上的指印以及粘连胶带上的指印。与常规方法相比,优势更为明显。结论水溶性荧光量子点ZnxCd（1-x）Se溶液显出的指印纹线细腻流畅,在法庭科学领域具有很好的应用前景。     

Nondestructive Biological Evidence Collection with Alternative Swabs and Adhesive Lifters

In forensic science, biological material is typically collected from evidence via wet/dry double swabbing with cotton swabs, which is effective but can visibly damage an item's surface. When an item's appearance must be maintained, dry swabbing and tape‐lifting may be employed as collection techniques that are visually nondestructive to substrates' surfaces. This study examined the efficacy of alternative swab matrices and adhesive lifters when collecting blood and fingerprints from glass, painted drywall, 100% cotton, and copy paper. Data were evaluated by determining the percent profile and quality score for each STR profile generated. Hydraflock^® swabs, BVDA Gellifters^®, and Scenesafe FAST? tape performed as well as or better than cotton swabs when collecting fingerprints from painted drywall and 100% cotton. Collection success was also dependent on the type of biological material sampled and the substrate on which it was deposited. These results demonstrated that alternative swabs and adhesive lifters can be effective for nondestructive DNA collection from various substrates.     

Enhancing contrast of fingerprints on plastic tape

Many of the currently available fingerprinting methods have limited ability to visualize fingerprints on plastic tape without expensive equipment or significant handling of the sample. This is especially true for visualizing fingerprints on black electrical tape. This study sought a hands-off method to produce easy visualization of fingerprints on different types of plastic tape, including black electrical tape, without the need for expensive equipment. The methods selected were to sublime disperse dyes into the tape, both with and without the fuming of cyanoacrylate, everywhere except for where the fingerprint was applied. The resulting color contrasts provided enough differentiation to visualize fingerprints on plastic tape under ambient light. Sequential fuming with cyanoacrylate followed by disperse dyes provided the best visualizations on all tapes, and cyanoacrylate followed by disperse yellow 211 clearly visualized fingerprints on black electrical tape.     

Fingerprints and DNA: STR typing of DNA extracted from adhesive tape after processing for fingerprints

An exhibit that is often received for examination in cases of robbery or terrorist activity is adhesive tape. This type of exhibit can often, but not always, be successfully processed for fingerprints. The question arises whether or not it is possible to extract and type DNA after the tape has been sequentially processed for fingerprints. In this work, various donors left fingerprints on the adhesive side of tapes. The tapes were then sequentially processed for fingerprints using an alternate light source, cyanoacrylate fuming, and staining with BY-40 and then crystal violet. DNA was subsequently successfully extracted, amplified and typed for six STR loci.     

Use of nitrogen cryogun for separating duct tape and recovery of latent fingerprints with a powder suspension method

Duct tape is sometimes recovered as physical evidence in crimes. The purpose of this study was to determine the quality of latent prints on the adhesive and non-adhesive surfaces of duct tape samples that were separated using three methods. Three hundred donor fingerprint impressions were deposited on duct tape. Sections of duct tape were affixed to sections of cardboard and a fingerprint placed on the non-adhesive surface of the tape. A second layer of duct tape was prepared and a fingerprint placed on the adhesive side of the tape and then the tape was affixed to the piece of tape on the cardboard. After a 24-h period, the samples were separated using gradual force, liquid nitrogen applied with a cryogun and an adhesive neutralizer to separate the layers of tape. The recovered fingerprints were processed with a fingerprint powder suspension method. The recovered fingerprint images were evaluated and rated as +1, +2, or +3. The liquid nitrogen spray separation method yielded the highest number of +3 prints.     

胶带粘面手印荧光显现剂的研发与应用

目的根据胶带粘面上潜在手印的特点,利用染料和潜手印的理化性质,研究开发胶带粘面手印荧光显现剂。方法在各种胶带粘面上显现潜在手印,并与常规的碳素墨水染色法进行比较。结果在长波紫外线照射下手印呈黄色明亮荧光,手印纹线清晰、连贯,基本不受手印遗留时间、客体表面颜色和性质的影响。结论胶带粘面上的汗潜手印和血潜手印用荧光显现剂显现效果优于碳素墨水染色法,在实际案件的侦破中有较好的应用前景。     

不同纸张上浓重红色印泥手印减薄的技术研究

目的建立有效的显现纸张上浓重的印泥手印方法。方法对普通材料纸和打印纸上的浓重红色印泥手印，通过指纹胶带提取转印、氧化漂白减薄、有机溶剂溶解减薄3种技术方法的减薄效果以及它们在减薄过程中的优缺点进行比较，得出适合于各种减薄技术的最佳试剂。结果本研究发现3种方法均可以有效地使浓重红色印泥手印清晰化，进而达到有效显现纸张上浓重的印泥手印的目的。     

利用CdSe巯基乙酸溶液显现水浸客体表面潜手印

目的研究水浸客体表面潜指纹的显现方法;方法利用CdSe巯基乙酸溶液显现被水浸泡过的黄色封箱胶带、黑色塑料袋、玻璃等常见非渗透性客体上的潜手印,讨论影响水浸非渗透性客体上潜手印显现效果的各种因素,并与传统方法进行比较,初步探讨了CdSe巯基乙酸溶液显现水浸非渗透性客体表面潜手印的方法;结果使用巯基乙酸包覆CdSe纳米复合材料显现潜在手印,使每分子纳米复合材料外表包覆足够数量的羧基,则可以提高它同手印残留物的结合能力,从而得到更高清晰度、更高分辨率的手印显像;结论巯基乙酸包覆CdSe纳米复合材料可以很好的显现水浸塑料、胶带等表面潜指纹。     

Combined DNA Typing and Protein Identification from Unfired Brass Cartridges,,,

Biological evidence analysis from contact traces is adversely affected by low quantity and quality of DNA. Proteins in these samples contain potentially individualizing information and may be particularly important for difficult surfaces such as brass, where DNA may yield incomplete profiles. In this study, touched unfired brass cartridges were sampled using dry tape or wet swabs and analyzed by separating DNA and protein from the same collected material, thus producing both genomic and proteomic information. DNA recovery was similar for both collection methods, with tape yielding an average of 1.36 ± 1.87 ng and swabs, 1.34 ± 3.04 ng. Analysis by mass spectrometry identified 95 proteins, with the two collection methods showing no significant difference (p = 0.76) in the average number of collected proteins: 44.5 ± 10.9, (tape) versus 47.9 ± 20.4 (swabs). Proteins can be collected from fingerprints at levels necessary to provide identifying information, thus expanding information obtained from challenging evidence.     

Lifting techniques for finger marks on human skin previous enhancement by Swedish Black powder — A preliminary study

An examination was done to investigate whether certain lifting techniques can lift recovered latent fingerprints on human skin surfaces of living subjects. For recovery Swedish Soot powder mixture (Swedish Black) was used.Donors intentionally placed fingerprints on the skin surface of living subjects. Finger marks were then in all cases recovered with Swedish Black powder. The procedure was repeated after 1 h and 4 h. Treated finger marks were secured and preserved as latent fingerprint evidence by different lifting processes. Having examined skin surfaces and finger marks we observed that the lifters such as white instant lifter, white fingerprint gelatin, black fingerprint gelatin, silicone, transparent adhesive tape, are suitable. Moreover, white fingerprint gelatin and white instant lifter proved to be very good at lifting treated finger marks. Black fingerprint gelatin was very good also, but finger marks were examined by slant light.     

Assessment of the methodology for estimating ridge density in fingerprints and its forensic application

In recent times, some studies have explored the forensic application of dermatoglyphic traits such as the epidermal ridge breadth or ridge density (RD) toward the inference of sex and population from fingerprints of unknown origin, as it has been demonstrated that there exist significant differences of fingerprints between sexes and between populations. Part of the population differences found between these studies could be of methodological nature, due both to the lack of standardisation in the position of the counting area, as well as to the differences in the method used for obtaining the fingerprint. Therefore, the aim of this study was to check whether there are differences between the RD of fingerprints depending on where the counting area is placed and how the fingerprints are obtained. Fingerprints of each finger were obtained from 102 adult Spanish subjects (50 females and 52 males), using two methods (plain and rolled). The ridge density of each fingerprint was assessed in five different areas of the dactylogram: two closer to the core area (one on the radial and the other on the ulnar side), two closer to the outermost area of each of the sides (radial and ulnar), and another one in the proximal region of the fingertip. Regardless of the method used and of the position of the counting area, thumbs and forefingers show a higher RD than middle, ring, and little fingers in both sexes, and females present a higher RD than males in all areas and fingers. In both males and females, RD values on the core region are higher than those on the outer region, irrespective of the technique of fingerprinting used (rolled or plain). Regardless of the sex and location of the count area (core or outer), the rolled fingerprints exhibit RD greater than that of the plain ones in both radial and proximal areas, whereas the trend is inverted in the ulnar area, where rolled fingerprints demonstrate RD lesser than that of the plain ones. Therefore, in order for the results of different studies to be comparable, it is necessary to standardise the position of the count area and to use the same method of obtaining the fingerprint, especially when involving a forensic application.     

热敏纸表面上汗潜指纹的显现

茚三酮溶液显现法是显现普通纸表面汗潜指纹的常用方法。但是由于热敏纸表面涂有热敏涂料,使得上述方法在该客体表面汗潜指纹的显现中难以奏效。不过,在此方法基础上改良发展而来的1,2茚二酮法、二甲基氨基肉桂醛法、过量丙酮冲洗法、半醇酮茚显现法等4种方法能取得较好效果。     

CdSe/TGA与CdS/PAMAM量子点溶液显现胶带粘面油汗手印性能比较研究

目的比较巯基乙酸包覆的硒化镉（CdSe/TGA）和硫化镉/聚酰胺-胺（CdS/PAMAM）量子点溶液显现胶带粘面手印的性能。方法两种材料在显现指纹的过程中,通过比较观察显现时间、显现温度、遗留时间等因素来考察显现效果。结果 CdSe/TGA溶液的荧光强度、显现时间以及材料的稳定性较好;CdS/PAMAM溶液显现的手印纹线流畅,显现细节特征能力强,对陈旧的或微弱的油潜手印的显现效果好。结论两种材料各有所长,对胶带粘面手印有良好的显现效果。     

Development of latent fingerprints on compact disc and its effect on subsequent data recovery

Chance fingerprints may be found on every type of surfaces of contact and when they are latent, need to be developed by various methods. The type of surface on which latent prints are to be developed is one of the important factors when a choice for a method of development is to be made. The matter becomes more crucial when the surface is unique like a compact disc containing digital data. In this case, to develop the fingerprints is not the only matter to be taken care of but also, is very important to select such a method which may not effect the stored data and its retrieval. In present investigation, various methods have been tried to develop fingerprints on the writing surface of a CD and results are discussed with respect to their development as well as its effect on stored data and data retrieval.     

Presentation of fingerprints of cadavers after an extended period of time, and also immersed cadavers

Dactyloscopic fingerprints of longer time in water laying corpses can be taken from the surface and rear face of the epidermis and from the corium with a simple method. Used are in household occurring or easily available substances. For best results in identification it is important to get all fingerprints without exchanging them.     

Raman identification of drug of abuse particles collected with colored and transparent tapes

Raman microscopy is a useful tool for the analysis of drug particles collected with adhesive tapes. In this work, first, the spectra of thirty drugs of abuse, degradation products, metabolites, and common cutting agent standards were recorded and the Raman bands observed were summarized providing the forensic analyst useful information for the identification of drug evidence. Then, the collection of different drug particles by a fingerprint lifting tape commonly used to remove and store fingerprints and fibers, and a white and green packaging tape, followed by the subsequent identification of the drugs by confocal Raman spectroscopy was performed. The particles were analyzed on top of the tapes, trapped between glass slides and the tapes, trapped in the tape folded over itself in the case of the transparent tape, and after folding and unfolding the tape in the case of the colored tape. The results obtained by the different approaches show that both tapes did not compromise the drugs spectra. However, the use of transparent tape is preferred because this tape allows the previous visual detection of the particles. Finally, several drug and sugar particles were spread over a clean table and inside a pocket, and the particles were collected with transparent tape and then properly identified. Although good results were obtained in both cases, the amount of fibers and other substances present in the collection area made the previous detection of the particles difficult and increases the analysis time.     

Effect of Aging and Surface Interactions on the Diffusion of Endogenous Compounds in Latent Fingerprints Studied by Mass Spectrometry Imaging,

The ability to determine the age of fingerprints would be immeasurably beneficial in criminal investigations. We explore the possibility of determining the age of fingerprints by analyzing various compounds as they diffuse from the ridges to the valleys of fingerprints using matrix‐assisted laser desorption/ionization mass spectrometry imaging. The diffusion of two classes of endogenous fingerprint compounds, fatty acids and triacylglycerols (TGs), was studied in fresh and aged fingerprints on four surfaces. We expected higher molecular weight TGs would diffuse slower than fatty acids and allow us to determine the age of older fingerprints. However, we found interactions between endogenous compounds and the surface have a much stronger impact on diffusion than molecular weight. For example, diffusion of TGs is faster on hydrophilic plain glass or partially hydrophilic stainless steel surfaces, than on a hydrophobic Rain‐x treated surface. This result further complicates utilizing a diffusion model to age fingerprints.     

Imaging electrostatic fingerprints with implications for a forensic timeline

The electrical charge deposited by contact electrification due to a finger touching a thin insulating surface is imaged using an electric field microscopy system. It is based on an ultrahigh impedance electric potential sensor used as a non-contact raster scanning probe to measure surface charge density with a spatial resolution of up to 5 μm. Preliminary results are presented which yield two principle findings. First, they indicate that the spatial resolution of the fingerprint image is sufficient for identification purposes. Secondly, that the decay of the surface charge may be considered as a candidate method for the dating or sequencing of these electrical charge fingerprints. The decay of surface charge with time is well defined, largely material dependent, and may take many days. This intrinsic decay rate for the material may be quantified using the charge imaging system described in this paper and a known test charge. The measurement technique described is non-destructive, may be repeated without degradation of the sample, and does not preclude the subsequent use of other techniques such as DNA analysis or conventional latent fingerprint development.     

基于PolyCyano UV粉末显现手印的新技术

目的介绍1种新型PolyCyano UV粉末显现非渗透性光滑客体表面潜手印的新技术。方法选取多种常见客体,由志愿者在客体上捺印指印,将PolyCyano UV粉末加热至230℃使其升华,待该粉末在手印纹线上聚合后使用长波紫外线照射若干时间,然后在蓝光激发下使用滤色镜观察并拍照。结果绝大部分非渗透性光滑客体表面上的潜手印均有很好的显现效果,尤其是对浅色或白色客体有十分明显的荧光效果,对陈旧手印也有较好的显现效果。结论该方法熏显操作简便、显现时间短、无需二次染色增强、不破坏生物检材、显现效果明显,适合推广使用。