Fluorescence of 1,2‐Indanedione with Amino Acids Present in the Fingerprint Residue: Application in Gender Determination

1,2‐indanedione is used for latent fingerprint visualization on porous surfaces. In this paper, fluorescence spectra of 1,2‐indanedione after reacting with 21 individual amino acids present in latent fingerprints residue were measured in water‐methanol solutions. The fluorescence intensity depends on the amino acid used, while the fluorescence peak does not change much. The concentration of amino acids in fingerprint residue in females is almost the double of their concentration in males. This property combined with fluorescence of 1,2‐indanedione‐amino acids compounds is used for gender determination, by comparing the fluorescence intensity peaks in the same experimental conditions. In this preliminary study, the fluorescence signal from the samples representing females was almost two times the signal for samples representing males. In addition to the reduction by almost 50% of the number of suspects in a criminal research case, these results could be helpful in gaining some knowledge about the papillary residue composition.     

The effect of 1,2-indanedione,a latent fingerprint reagent on subsequent DNA profiling

The compound 1,2-indanedione was recently introduced in our laboratory as an operational reagent for developing latent fingerprints on porous surfaces. As part of the reagent implementation, a study was carried out in order to determine whether either of the two operational 1,2-indanediones formulations interferes with further DNA profiling. Both formulations are based on HFE7100 solvent. One is acidic and the other neutral. In a controlled experiment, known donors attached stamps to envelopes by licking them. The stamped envelopes were initially treated with either one indanedione formulation or the other, and DNA was then extracted for STR typing. No differences were observed between the STR profiles obtained from treated and untreated stamps and envelopes, indicating that 1,2-indanedione does not adversely affect the extraction and subsequent amplification of the STRs examined. However, preliminary results indicate that potential DNA analysis depends on the time interval between the indanedione treatment and DNA extraction as no DNA can be recovered six days following treatment. For this reason, it is strongly recommended to extract DNA from treated items of evidence as soon as possible after indanedione treatment.     

Latent Fingerprint Development on Thermal Paper Using Traditional Ninhydrin and 1,2‐indanedione

Thermal paper poses a significant challenge to latent print development as it tends to change color when traditional fingerprint development formulations are applied to it. In this study, the optimal components of ninhydrin, 1,2‐indanedione, 1,8‐diazafluoren‐9‐one (DFO), and 5‐methylthioninhydrin (5‐MTN) for yielding clear fingerprints on thermal paper were determined by systematically adjusting the relative amounts of the reagents, polar solvents, and the nonpolar diluent petroleum ether, followed by validation on text‐printed thermal paper. Specifically, 3.0% ethyl acetate as the polar solvent in petroleum ether was found to be the optimal combination; the optimal dilution ratios of ninhydrin, DFO, and 5‐MTN original solutions with petroleum ether were 1 to 2, 11, and 7, respectively. The optimal concentration of 1,2‐indanedione in petroleum ether was 0.125 g/L, with a string of 0.5% ethyl acetate in petroleum ether.     

Fingerprint enhancement revisited and the effects of blood enhancement chemicals on subsequent profiler Plus fluorescent short tandem repeat DNA analysis of fresh and aged bloody fingerprints

This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S 1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity of the fluorescent signals was very similar and the allele size measurements remained constant and identical to those of untreated bloody fingerprints. No additional background fluorescence was noted. Continuous exposure (for 54 days) to two of the seven enhancement chemicals selected (i.e., Crowle's Double Stain and Hungarian Red) slightly reduced the amplification efficiency of the longer STR loci in profiles of fresh and 7 to 14-day-old bloodprints. This suggests that long-term exposure to these chemicals possibly affects the integrity of the DNA molecules. This study indicates that significant evidence can be obtained from fresh or aged bloody fingerprints applied to a variety of absorbent and nonabsorbent surfaces which are exposed to different enhancement chemicals for short or long periods of time. It also reaffirms that PCR STR DNA typing procedures are robust and provide excellent results when used in concert with fluorescence-based detection assays after fingerprint identification has taken place.     

纸张上潜在手印三种前处理方法对DNA检验的影响

目的通过比较常见纸张上潜在手印盲提法与显现后精准提取法的接触DNA检出率,探讨常见纸张上接触DNA前处理的优选方案。方法比较五种常见纸张上使用盲提法和显现潜在手印(茚二酮显现法、茚三酮熏显法)后精准提取法采集的接触DNA样本检出率。结果粗糙日历纸盲提的接触DNA检出率为17.8%,通过茚二酮法和茚三酮法显现的潜在手印所提取的DNA检出率分别为75.6%、77.8%;光滑日历纸三种方法所提取的接触DNA检出率为4.4%、11.1%、11.1%;A4复印纸三种方法接触DNA检出率为20%、37.8%、66.7%;牛皮纸三种方法接触DNA检出率为20%、68.9%、64.4%;快递纸袋的三种方法接触DNA检出率为2.2%、6.7%、46.7%。结论不同纸张上潜在手印经显现后接触DNA检出率不同,通过茚二酮或茚三酮显示潜在手印后精准提取DNA的前处理方法相较于盲提法的接触DNA检出率高。实战中可应用此类方法同时获得手印与DNA分型,以有效提高证据力。     

Systematic study on STR profiling on blood and saliva traces after visualization of fingerprint marks

This paper describes a systematic study of the influence of optical, physical, and chemical methods used for fingerprint enhancement on subsequent DNA analysis of biological stains. Latent fingerprints as well as fingerprints in contact with blood and saliva on different surfaces were treated with dactyloscopic methods. As a general finding, subsequent STR profiling of the blood/saliva traces led to good results after all the enhancement methods included in this study. Concerning blood enhancement procedures, the airbrush technique showed deleterious effects on subsequent STR analysis in some cases. We therefore recommend the implementation of the layer technique, as it brings advantages for fingerprint enhancement as well. It could also be shown that, as can be necessary in practical casework, two enhancement methods can be performed on a single stain without having influence on STR profiling. In terms of methodological variety, this paper reflects a comprehensive study performed on STR profiling after fingerprint enhancement methods, including rare methods and variations of techniques, which can be a useful alternative in certain case scenarios.     

Refreshing the Aged Latent Fingerprints with Ionizing Radiation Prior to the Cyanoacrylate Fuming Procedure: A Preliminary Study

One of the crucial factors determining the cyanoacrylate deposit quality over latent fingerprints appeared to be the extent of the humidity. This work focuses on the enhancement/refreshment of age‐degraded latent fingerprints by irradiating the samples with UV, X‐ray, or thermal neutrons prior to the cyanoacrylate (CA) fuming. Age degradation of latent fingerprints deposited on glass surfaces was examined through the decrease in the number of characteristic minutiae counts over time. A term “critical day” was introduced for the time at which the average number of identifiable minutiae definitions drops to one‐half. Fingerprints older than their “critical day” were exposed to either UV, X‐ray, or thermal neutrons. Identical reference samples were kept unexposed. All samples, both reference and irradiated, were developed during a single CA fuming procedure. Comparative latent fingerprint analysis showed that exposure to ionizing radiation enhances the CA fuming, yielding a 20‐30% increase in average minutiae count.     

Chemical development of latent fingerprints: 1,2-indanedione has come of age

The performance of 1,2-indanedione as a latent fingerprint reagent on some types of paper was found to exceed that of DFO, the leading fluorogenic fingerprint reagent. It even exceeds the performance of the sequence, DFO, followed by ninhydrin. No new prints could be observed when ninhydrin was applied after indanedione. On a large number of actual exhibits (used checks) indanedione developed 46% more identifiable prints than the sequence DFO-ninhydrin. A standard procedure for fingerprint development by indanedione is proposed. Best results are obtained with a 0.2% indanedione solution in HFE7100 solvent containing 7% ethyl acetate, but no acetic acid. It can be recommended to start using 1,2-indanedione, which is already commercially available, in actual fingerprint casework.     

Optimization and initial evaluation of 1,2-indandione as a reagent for fingerprint detection

1,2-Indandione has been used to develop fluorescent fingerprints on porous materials such as paper. The compound reacts with amino acid residues to produce highly fluorescent fingerprint ridges. An optimized formulation and treatment protocol for using the reagent is presented here. The reagent is applied as a solution in HFE7100 containing acetic acid and ethyl acetate. Treated articles are heated at 100 degrees C for 10 min at ambient humidity and stored in the dark before recording the fingerprints using fluorescence photography or digital imaging. Photodecomposition of the fluorescent fingerprints has been observed. Storage in the dark reduces degradation, extending the lifetime of the fingerprints. Other chemical methods to stabilize the fingerprints proved unsuccessful. Comparisons of the performance of 1,2-indandione with DFO in CFC113 performed on a limited range of substrates indicated that the reagent might be an effective method for the development of latent fingerprints despite the new reagent producing less intense fluorescence.     

STR genotyping and mtDNA sequencing of latent fingerprint on paper

A systematic study was conducted to investigate whether DNA can be successfully extracted from latent fingerprints deposited on ordinary paper and analysed using short tandem repeat profiling and mitochondrial DNA sequencing. In order to evaluate the performance of latent fingerprint analysis in a criminal case, experiments with varying conditions were carried out to improve our understanding of low copy number (LCN) DNA typing. After optimising the extraction methods to achieve increased sensitivity, the examination of touched paper can routinely yield the STR profile of the individual who has touched it. A fingerprint can therefore be considered as a potential source of DNA for genetic identification. Nevertheless, the findings of our "after enhancement experiment" (using chemically or physically pre-treated fingerprints), and our "mixture experiment" (using fingerprints from three to four people on the same sheet of paper) help to define the limitations of the low copy number PCR technique in forensic casework.     

一种改进的碘熏法-碘锌手印显现法

目的为解决传统碘熏法显出手印容易褪色、固定困难等问题。方法提出了一种改进的碘熏法-碘锌手印显现法，实验了不同反应物配比、不同客体材质对显现效果的影响；与常规碘熏法进行了对比实验；并考察了碘锌法显出手印的稳定性。结果碘锌手印显现法可以用于常见渗透性及非渗透性客体上新鲜汗潜手印的显现。该方法不必外加热源，携带、存储和应用更加便利；该方法显出的指纹纹线保存时间与传统碘熏法相比明显延长。结论碘锌手印显现法是一种高效、实用的手印显现方法。     

Comparative study of electrochromic enhancement of latent fingerprints with existing development techniques

To address the challenge of capturing latent fingerprint evidence from metal surfaces, a new method of latent fingerprint enhancement based on electrochromic polymer films has recently been developed. Here, we present a study comparing the development and visualization of nonvisible fingerprints on stainless steel substrates using this electrochromic enhancement approach with three classical methods (dusting, wet powder, and cyanoacrylate fuming). Two variants of the electrochromic enhancement method were utilized with polyaniline and poly(3,4-ethylenedioxythiophene) as the electrochromic materials. Fingerprint samples were taken from different donors (varying in age and gender) and were exposed to different environments for systematically varied periods of time (up to 28 days). The environments represent plausible evidential scenarios: left under ambient conditions, washed with aqueous soap solution, washed with acetone, submerged in water, and maintained at elevated temperature. The electrochromic enhancement procedure frequently outperformed the traditional methods, particularly for samples exposed to more challenging histories.     

Recovery of DNA from Latent Fingerprint Tape Lifts Archived Against Matte Acetate

This study was driven by court order to examine methods to remove, extract, and STR‐type potential DNA entrapped between latent fingerprint lifting tape and matte acetate that was collected from a 1977 crime scene. Results indicate that recovery of appreciable quantities of DNA is more challenging once adhesive is attached to matte acetate cards and even more difficult when fixed following black powder enhancement. STR amplification of extracts from entrapped fingermarks collected following the dusting/lifting procedure did not produce robust profiles, and extraneous peaks not expressed by print donors were detected for some samples. A hearing was set to argue whether there was DNA remaining to be tested, and if so, whether that DNA could be exculpatory in this postconviction matter. The studies herein provided the basis for the court's decision to not require the testing.     

The use of liquid latex as a pre-treatment to recover debris-covered latent fingerprints from exterior surfaces of vehicles

This study evaluated the effectiveness of using liquid latex as a pre-treatment for fingerprint recovery from the exterior surfaces of vehicles in summer. The sample of this study was 540 sebaceous latent fingerprints deposited on the lower body of three vehicles. Thirty control and thirty experimental fingerprints were deposited on each vehicle, and the experiment was repeated three times. The three vehicles were driven daily for either 2, 3, or 4 weeks after the deposition of fingerprints. After the vehicles reached their designated debris accumulation duration, the latent fingerprints in the control groups were developed with black fingerprint powder. Liquid latex was applied onto the fingerprints in the experimental groups, and they were subsequently developed with black fingerprint powder. A chi-sure test indicated that there was a significant difference in fingerprints recovery performance between two methods (X² = 4.903, d.f. = 1, p = 0.027). An odds ratio test indicated the control method increases the probability of fingerprint recovery by 1.54 times. A Fisher's exact test was used to evaluate the quality of fingerprints recovered from both methods and it indicated that there is no significant difference in quality using the two methods (p = 0.058). This study indicated that the traditional fingerprint powder method performed better for fingerprint recovery from exterior surfaces of vehicles in summer.     

Ninhydrin Thiohemiketals: Basic Research Towards Improved Fingermark Detection Techniques Employing Nano‐Technology*

Abstract: In the first part of a comprehensive research project towards more efficient application of nano‐technology to fingerprint visualization, we investigated the possibility of more selective binding of gold nanoparticles (NP) to fingerprint material. We synthesized derivatives of ninhydrin and 1,2‐indanedione containing loosely bound thiol groups. In particular: thiohemiketals (THK) of ninhydrin, and thioketals of 1,2‐indanedione were prepared and tested as potential fingerprint reagents. By reacting ninhydrin with various thiols we were able to produce a series of novel THK, bearing the SR group always at C2. Ninhydrin THK reacted with amino acids to produce the expected Ruhemann’s purple, and they also developed latent fingermarks on paper in a similar manner to ninhydrin. Ketals and thioketals derived from 1,2‐indanedione reacted neither with amino acids nor with latent fingermarks. In the second part of the research, the thiols which are formed on the ridges as byproducts of the reaction with amino acids will be tested for their potential as stabilizers for gold NP that will become covalently bound to the fingerprint ridges.     

The effect of mark enhancement techniques on the presumptive and confirmatory tests for blood

An investigation into the effects of physical and chemical enhancement on subsequent presumptive and confirmatory tests for human blood is presented. Human blood was deposited onto porous (white 80 gsm paper and brown envelope) and non-porous (tile and linoleum) substrates in a depletion series (30 depletions on non-porous and 20 on porous) and subjected to three ageing periods; 1, 7 and 28?days. A number of enhancement techniques were tested [fluorescence, black magnetic powder (BMP), iron-oxide black powder suspension (PS), cyanoacrylate (CA) fuming, acid violet 17 (AV17), acid yellow 7 (AY7), ninhydrin, DFO and Bluestar Forensic Magnum (BFM) luminol] to evaluate their potential effects on subsequent presumptive and confirmatory tests. AV17 and Bluestar provided the best enhancement and fully enhanced all depletions in the series. The sensitivity of the Kastle-Meyer (KM) (presumptive), Takayama and RSID-Blood tests (confirmatory) was initially investigated to determine the range of detectable depletions. The KM test detected all depletions, whereas the Takayama test detected up to depletion 6 and RSID-Blood detected up to depletion 20 (paper), 10 (envelope), 15 (tile) and 9 (lino). The abilities of these tests to detect blood after enhancement were then observed.A number of techniques resulted in little to no effect on any of the blood tests, whereas adverse effects were observed for others. Ninhydrin and CA fuming caused weak but instantaneous positive KM results whereas methanol-based AV17 and AY7 delayed the reaction by as much as 1?min. The Takayama test was not very sensitive, therefore, its performance was easily affected by enhancement and negative results were often observed. RSID-Blood tests were largely unaffected by chemical enhancement although a drop in positive results was observed for some of the techniques when compared to positive controls.Using a standard procedure for DNA extraction, all the tested blood samples (before and after enhancement) gave a detectable quantity of DNA and were successfully profiled. Out of the 45 samples processed for DNA profiling, 41 gave full profiles, while the remaining showed allele drop out in one or two loci.     

Enhancement of Latent Fingerprints on Fabric Using the Cyanoacrylate Fuming Method Followed by Infrared Spectral Mapping

A method has been developed for the visualization of latent fingerprints on fabrics, which is based upon cyanoacrylate (superglue) fuming followed by imaging using an infrared microscope. Results show that imaging on smooth, shiny fabrics such as polyester, silk, nylon, and acetate of different colors and patterns can give an improvement over existing enhancement methods. Results for cotton and polycotton were less successful and it is thought this may be due a combination of the presence of the carbonyl functional group in these fabrics as well as their absorbency to fingerprint sweat. The carbonyl peak (1700 cm^?1) provided the optimum spectroscopic feature to map and image a fingerprint. Comparisons between infrared mapping at a specific frequency range and principal component analysis showed that improved imaging was obtained with principal component analysis.     

“502”加膜一染色法显现油质手印

目的探索方便快捷并有效的油质手印显现方法。方法用“502”熏显常见玻璃、粗糙皮革等不同客体上不同遗留时间的油汗手印和多油手印,加染后用透明胶带粘取。结果显现了30天左右大多数非渗透性客体上的油质加层手印,10天左右渗透性客体上的油质渐层手印。结论本方法适用于油质加层手印及部分油质渐层手印的显现,显出手印清晰,流畅,不破坏手印。     

Visualization of latent fingerprint corrosion of metallic surfaces

Abstract:  Chemical reactions between latent fingerprints and a variety of metal surfaces are investigated by heating the metal up to temperatures of ∼600°C after deposition of the fingerprint. Ionic salts present in the fingerprint residue corrode the metal surface to produce an image of the fingerprint that is both durable and resistant to cleaning of the metal. The degree of fingerprint enhancement appears independent of the elapsed time between deposition and heating but is very dependent on both the composition of the metal and the level of salt secretion by the fingerprint donor. Results are presented that show practical applications for the enhancement to fingerprints deposited in arson crime scenes, contaminated by spray painting, or deposited on brass cartridge cases prior to discharge. The corrosion of the metal surface is further exploited by the demonstration of a novel technique for fingerprint enhancement based on the electrostatic charging of the metal and then the preferential adherence of a metallic powder to the corroded part of the metal surface.     

京尼平显现渗透性客体上潜在手印方法研究

目的介绍一种能够用来显现潜在手印的新型物质—京尼平。方法依据京尼平能和手印遗留物质中的氨基酸或蛋白质发生反应,生成一种有荧光效应的多聚体深蓝色物质,通过自然光或多波段光源下显现观察,并将其与传统的茚三酮、DFO显现进行比较。结果京尼平显现法的显现条件与茚三酮类似,其处理后的潜在手印既在自然光下可见又在多波段光源的激发下有荧光现象。结论京尼平显现法可用于渗透性客体上潜在手印的显现。