Fingerprint Powder Research Articles

Enhancement of latent fingerprints on the adhesive side of tapes using various methods.

Fingerprints are well known to be an important aspect of a criminal investigation due to their ability to identify an individual. Today, there are numerous methods to enhancing latent fingerprints. Some of these methods were performed on the adhesive side of various types of tapes in order to determine which method produced the greatest print development. The methods used were: dusting using various powders, small particle reagent (SPR), crystal violet, and cyanoacrylate fuming. Only two of the techniques used preformed well across a majority of the tapes. Even though all of the techniques did not preform well on all of the tapes they gave some valuable information that could be used to better results. The most successful techniques were the cyanoacrylate fuming and crystal violet. Both of these methods developed prints that were detailed with superior contrast compared to the other methods performed. Even though both techniques were superior, the cyanoacrylate fuming developed the higher quality prints. The cyanoacrylate fuming performed greatest when fumed with water for humidity followed by a dusting of fingerprint powder. These two methods were both simple to perform and were completed within a timely manner. Overall, the cyanoacrylate fuming could be preformed more efficiently because multiple prints could be developed at one time.

Ultrabright Fluorescent Silica Nanoparticles Embedded with Conjugated Oligomers and Their Application in Latent Fingerprint Detection.

Fluorescent micro- and nanosized particles have a broad range of applications in biology, medicine, and engineering. For these uses, the materials should have high emission efficiency and good photostability. However, many organic fluorophores suffer from aggregation-induced quenching effects and photobleaching. Here, we used a simple method based on covalently blending a fluorescent conjugated oligomer with silica nanoparticles to achieve emission quantum yields as high as 97%. The resulting system also showed excellent stability under continuous light illumination, in a range of pH values and temperatures, and in common solvents. This fluorescent material showed outstanding properties, including highly efficient blue emission, low cost, low toxicity, and easy synthesis. Furthermore, its effectiveness for latent fingerprint detection was demonstrated as a proof of concept on various substrates. The obtained emissive fingerprint powder gave good optical/fluorescent images with high contrast and resolution between the ridges and spaces.

Typing DNA profiles from previously enhanced fingerprints using direct PCR

Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold® DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered ‘up-loadable’ to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks.

DNA recovery from latent fingermarks treated with an infrared fluorescent fingerprint powder

The effect of the infrared fluorescent fingermark visualisation powder, fpNatural 1™, on the recovery of both the quantity and quality of touch DNA from fingerprints deposited on glass slides, was investigated using qPCR and STR typing. Four donors each deposited replicate marks, which were either left untreated (n=5) or treated by dusting with fpNatural 1™ (n=5). Each sample was swabbed using the double swab technique, before being extracted using the EZNA Forensic DNA kit and then DNA quantitated before being subjected to DNA profile analysis. Results showed that there was no significant effect of fpNatural 1™ on either the quantity or quality of recovered DNA. This suggests that fpNatural 1™ may prove a good choice of powder for regular use at crime scenes or in the laboratory. The fpNatural 1™ properties of low density, water immiscibility and low DNA affinity may account for these positive outcomes.

Autopsy Fingerprint Technique Using Fingerprint Powder.

The collection of high-quality fingerprints is an important component of routine forensic autopsies and represents one of the several potential methods for identifying a decedent. Fingerprint collection at autopsy frequently employs a manual method using fingerprint ink and cards, although some offices use digital-scanning equipment. While these methodologies are adequate in most circumstances, this study introduces an alternative method using fingerprint powder and adhesive labels. The method is quick, easy to perform, and cost-effective and provides the additional advantage of an adhesive label that easily conforms to the finger, palm, or foot which reduces smudging of prints in individuals with rigor mortis, skin slippage, or decomposition compared to more traditional autopsy fingerprint collection techniques. The prints can then be easily stored, either in hard-copy form or scanned to make a digital record.

THEORETICAL AND PRACTICAL ASPECTS OF POSSIBILITIES OF VISUALIZATION AND RECOVERY OF PAPILLAE PATTERN PRINTS FROM BIOLOGICAL SURFACES

The aim of the authors’ experiment conducted was to find out whether it is possible to find, visualise and recover papillae pattern prints from the surfaces of fruits, vegetables and plant leaves. The experiment was performed in four stages. The first stage was performed in the room where the temperature varied from 21°C to 25°C and the time periods were as follows: prints were visualised and copied immediately after leaving them, in 1 hour after leaving them, as well as in 24 hours, in 48 hours, in 72 hours and in 120 hours after leaving the prints. 217 papillae pattern prints were left on the surfaces of fruits and vegetables. 119 of them were recognised as valid for person identification. The second stage was performed under natural weather conditions with the air temperature from 14°C to –20°C. The fruits and vegetables were not covered so that they could not be affected by the meteorological conditions. The time periods were as follows: prints were visualised and copied immediately after leaving them, in 12 hours, in 24 hours and in 36 hours after leaving the experimental prints. As the result 176 papillae pattern prints were left on the surfaces if fruits and vegetables. 43 of them were recognised as valid for person identification. The third stage was performed in the room where the temperature varied from 21°C to 25°C. Experimental papillae pattern prints were left on the leaves of dandelion, apple tree, birch, plantain, clematis and bent-grass. Immediately after leaving the prints they were processed with black fingerprint powder and copied by white Mikrosil silicon casting material. As the result 13 papillae pattern prints were left on the surfaces of plant leaves. All of them were recognised as valid for person identification. Whereas, in the fourth stage plant leaves were exposed to the influence of meteorological conditions (air temperature varied from 28°C to 34°C, it was almost sunny, the slow wind, a bit rain) for time periods of 24 hours and 48 hours. As the result 65 papillae pattern prints were left on the surfaces of plant leaves. 11 of them were recognised as valid for person identification. The summary of the results obtained during the experiment and the analysis let to conclude that: it is possible to find, visualise and recover papillae pattern prints from the surfaces of fruits, vegetables and plant leaves by using powder method which can be used both on scene and under laboratory conditions; there is no set proportionality between number of prints left and prints valid for person identification; quality of prints is not always influenced by preservation time period of prints; meteorological conditions have essential influence on the quality of prints in the preservation time period of prints.

비 다공성 표면에서 천연분말로 현출된 잠재지문의 농도계 이미지분석을 이용한 예비적인 반 정량적 평가

범죄현장조사에 사용되는 인체에 유해할 수 있는 일반분말에 대한 대체수단으로 천연분말(오징어 먹물분말, 청대분말, 쌀분말)을 이용하여 비 다공성표면(유리, 플라스틱, 타일)상의 잠재지문을 현출(가시화)하였다. 현출된 잠재지문을 Automatic Fingerprint Identification System (AFIS)으로 분석한 특징점의 수를 흑색분말을 사용한 결과 특징점 수와 비교하였으며 또한 객관적이고 계량적인 평가방법의 개발을 위하여 각 분말로 가시화된 지문의 이미지를 농도계 이미지분석(densitometric image analysis)을 이용한 결과 값인 융선 피크의 면적값을 비교하였다. 천연분말들의 현출효과는 표면에 따라 다양하게 나타났다. 일반적으로 오징어 먹물분말은 대부분의 표면에서 좋은 현출을 보였으며 청대분말은 타일표면에서 그리고 쌀분말은 유리표면에서 최고의 현출을 보였다. 그러나 플라스틱 표면은 천연분말에 의한 지문현출이 가장 어려운 표면이었다. Field Emission Scanning Electron Microscope (SEM)를 이용한 이미지 분석에서 융선에 적절한 흡착력을 가지는 조건으로 천연분말 입자의 크기와 형태가 중요한 인자임을 확인할 수 있었다. 비록 기술적인 어려움으로 특징점의 수와 융선 피크의 면적값과의 상관관계를 볼 수는 없었으나 공평하고 객관적인 지문의 평가방법으로 기준 이미지의 사용을 통한 이미지 보정을 통하여 가능하리라고 사료된다. 저가의 저독성 천연분말은 추가적인 실험을 통하여 적절한 잠재지문 현출제로서의 가능성을 보일 것으로 사료된다. Conventional fingerprint powders used during crime scene investigations pose potential health hazards. Thus, multiple natural replacement powders, including squid ink powder, indigo and rice powder were used to develop (visualize) latent fingerprints on non-porous surfaces (e.g., glass, plastic and tile). Fingerprints developed using the natural powders were compared using the Automatic Fingerprint Identification System (AFIS) with those developed with traditional black powder. The peak areas of ridges were also compared using densitometric image analyses. Collectively, objective and quantitative evaluation methods were developed. The effectiveness of natural powders varied depending on the surface but, in general, squid ink powder performed well on most surfaces. Indigo powder performed well on tile surfaces, while rice powder performed well on glass surfaces. Plastic was the most difficult surface from which to develop fingerprints. Image analysis using Field Emission Scanning Electron Microscopy (SEM) demonstrated the importance of the size and shape of natural powder particles to properly adhere to the ridges. Although densitometric image analyses did not correlate the number of minutiae and ridge peak areas, an unbiased, objective evaluation method would be possible using image analyses with a reference image. Additional experimentation will yield safe and cost-effective natural powders with which adequate fingerprint development can be performed.

Allergic reaction from fingerprint kit attributable to unlabeled gluten, probable wheat flour

Allergic reaction from fingerprint kit attributable to unlabeled gluten, probable wheat flour

New incompatibilities uncovered using the Promega DNA IQ™ chemistry

Over the years, the Promega DNA IQ™ System was proven an effective technology for the production of clean DNA from a wide variety of casework specimens. The capture of DNA using the DNA IQ™ paramagnetic beads, however, was shown to be affected by a few specific chemicals that could be present on exhibits submitted to the laboratory. In this study, various blood and latent fingerprint enhancement reagents/methods, marker pens and adhesive tapes, applied at the crime scene or in the forensic laboratory on casework exhibits or used to collect biological material, were tested for their compatibility with the DNA IQ™ technology. Although no impact on DNA recovery was observed for most reagents, the MAGNA™ Jet Black fingerprint powder and three 3M Scotch® adhesive tapes were shown to severely or completely inhibit DNA binding onto the DNA IQ™ beads. The effect of MAGNA™ Jet Black on DNA recovery could be counteracted by separating the magnetic powder from the lysates by centrifugation or filtration, prior to DNA extraction. High quality STR profiles were obtained from samples subjected to MAGNA™ Jet Black suggesting it does not impact DNA integrity.

Improvement in fingerprint detection using Tb(III)-dipicolinic acid complex doped nanobeads and time resolved imaging

This paper deals with the synthesis and application of lanthanide complex doped nanobeads used as a luminescent fingerprint powder. Due to their special optical properties, namely a long emission lifetime, sharp emission profiles and large Stokes shifts, luminescent lanthanide complexes are useful for discriminating against signals from background emissions. This is a big advantage because latent fingerprints placed on multicoloured fluorescent surfaces are difficult to develop with conventional powders. The complex of 2,6-dipicolinic acid (DPA) and terbium ([Tb(DPA)3]3−) is used for this purpose. Using the Stöber process, this complex is incorporated into a silica matrix forming nanosized beads (230–630nm). It is shown that the [Tb(DPA)3]3− is successfully incorporated into the beads and that these beads exhibit the wanted optical properties of the complex. A phenyl functionalisation is applied to increase the lipophilicity of the beads and finally the beads are used to develop latent fingerprints. A device for time resolved imaging was built to improve the contrast between developed fingerprint and different background signals, whilst still detecting the long lasting luminescence of the complex. The developed fingerprint powder is therefore promising to develop fingerprints on multicoloured fluorescent surfaces.

Evaluation of Four Fingerprint Development Methods for Touch Chemistry Using Matrix-Assisted Laser Desorption Ionization/Time-of-Flight Mass Spectrometry(.).

Four preparation techniques for MALDI/TOF mass spectrometry were compared to determine the ability to gather intelligence for investigations through the chemical analysis of latent fingerprints, defined as "touch chemistry." Compatible fingerprint development processes used for identification along with new techniques are necessary to evaluate touch chemistry. Ten volunteers deposited fingerprints from solvent residues containing drugs and explosives onto microscope slides. The developers included (A) fingerprint powder, (B) MALDI matrix, (C) fingerprint powder and lifting, and (D) cyanoacrylate fuming with fingerprint powder. Qualitative identification was based on ion images and spectra. The highest average detection rates (88%) were found using methods A and B. Methods C (52%) or D (18%) had limited success. Results demonstrate the importance of imaging coupled to extracted mass spectral data in detecting analytes in deposited fingerprints. Overall, the results suggest continued development of touch chemistry applications could prove useful for gathering intelligence and forensically relevant information.

Investigating the potential of fluorescent fingerprint powders as a marker for blow fly larvae (Diptera: calliphoridae).

Four fluorescent fingerprint powders (RedWop(™) , GreenWop(™) , Basic Yellow(™) , and Yellow Powder(™) ) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow(™) and RedWop(™) caused higher larval mortality. Basic Yellow(™) delayed development and adult emergence while RedWop(™) and Yellow Powder(™) had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (<10%) or topically, with GreenWop(™) demonstrating minimal adverse effects. Optimum wavelength for discrimination between powders was 450nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.

Comparison of practical techniques to develop latent fingermarks on fired and unfired cartridge cases

We have tested some widely used and practical fingermark enhancement techniques such as powdering (regular powder dusting and magnetic powder application), cyanoacrylate fuming, fluorescent dying (basic yellow 40), gun blueing solutions and acidified hydrogen peroxide solutions. The results were evaluated and compared in order to establish best procedures on processing cartridge cases. The tests were performed on brass discs subjected to three different temperatures (room temperature, 63 and 200°C), and on fired and unfired cartridge cases. All the samples were processed after three different periods of time (24h, 7 days and 14 days) after deposition. The best results for both fired and unfired cartridge cases were obtained by the sequential application of cyanoacrylate, gun blueing solution and basic yellow 40. Some stages of the firing process were isolated in order to identify their effects over the final amount and quality of the remaining latent fingermarks on cartridge cases. Good state fingermarks were developed on unfired cartridge cases cycled through the gun, showing that friction inside the gun without firing does not cause significant damage to the fingermarks. On the other hand, fired cartridge cases are significantly affected by the firing effects, exhibiting low quality ridge details which are mainly located next to base. An unexpected phenomenon was observed on most of the brass discs heated to 200°C and developed with gun blueing solutions; they presented a reverse development compared to the expected one, with darkening of the ridges instead of the background.

A systematic study to understand the effects of particle size distribution of magnetic fingerprint powders on surfaces with various porosities.

This study intends to design magnetite (Fe3 O4 )-based magnetic fingerprint powders with different particle size distributions. It also investigates the influence of particle size distribution on the visualization of latent fingermarks with as little background staining as possible on the surfaces with various porosities in a systematic way. Two strategies were used to prepare the magnetic fingerprint formulations for this study: milling of coarse magnetite particles for different durations, and mixing of sieved fine particles with different size ranges with coarse particles. Particle size analyses of the prepared magnetic powders, optical microscopy-based roughness analysis of the surfaces and SEM measurements of the visualized fingerprints and representative powders were performed. Mag2 of the formulations prepared through milling and Mag5 and Mag6 of the formulations prepared through sieving and mixing were more successful in the development of latent prints than the rest of the solutions.

Fingermark recovery from riot debris: Bricks and stones

During the UK riots in August 2011, large volumes of bricks and stones were used as weapons or projectiles in acts of violence or to gain illegal entry to properties. As a result, it has been emphasised that it is necessary to determine suitable chemical treatment(s) that will enable the development of fingermarks on such items in order to identify those involved. This study has undertaken the task of attempting to develop latent fingermarks on common house bricks, limestone and sandstone using current techniques including ninhydrin and fluorescence. Results produced have shown that, with fluorescent fingerprint powder, silver nitrate and superglue providing the best results, it is now possible to enhance fingermarks that were previously left undeveloped. In addition, Isomark T-1 Rapid Grey High Resolution Forensic Impression Material has proved extremely effective as an alternative method of recovering fingermarks developed with fluorescent fingerprint powder.

Seeing into the infrared: A novel IR fluorescent fingerprint powder

A preliminary study demonstrates that latent fingermarks across a range of highly patterned, coloured non-porous and semi-porous substrates may be clearly developed and imaged in the near infrared following a simple dusting method using finely divided spirulina platensis powder, a naturally occurring, non-toxic algae, used widely within the food industry. Troublesome printed/multicoloured backgrounds show less interference with the fluorescence observed using this material, unlike conventional luminescent powders which fluoresce in the visible spectrum alongside the background to which they are applied. The material shows promise for use both in the field and in the laboratory.

Activities Designed for Fingerprint Dusting and the Chemical Revelation of Latent Fingerprints

This article describes two different latent fingerprint revelation activities that have similar organization structures and pedagogy methodologies. The two activities feature the use of multiple stations to allow students to test, compare, and contrast different fingerprint revelation techniques. Both activities adopt a structured-inquiry pedagogical methodology that invites students to form their own opinions on the strengths and weaknesses of each technique. Fingerprint dusting techniques are more accessible because there is less need for fume hoods and protective safety equipment. The chemical revelation of latent prints techniques are more suited for a laboratory environment where fume hoods and protective safety equipment are available.

New Visualizing Agents for Developing Latent Fingerprints on Various Porous and Non-Porous Surfaces Using Different Household Food Items

Most of the time it is seen that the conventional fingerprint powders used for developing latent fingerprints aretoxic and pose potential health hazards. In order to overcome this disadvantage I have attempted to use new powders for developing latent fingerprints which are simple, non- toxic, less expensive than the commercially used fingerprint powders. These are easily available in every house. In the present study a preliminary attempt has been made to develop latent fingerprints with commonly used household kitchen food products such as cocoa powder, custard powder, corn flour, baking soda, baking powder, black salt, edible food (orange colour) and turmeric powder. This type of work has not been reported previously and can provide useful information to the investigators in cases of scarcity or non-availability of regular conventional fingerprint development powders. The use is simple and a novice in the field of forensic fingerprinting can also do it.

Fingerprint Recovery from Human Skin by Finger Powder

An examination experiment has been carried out to investigate whether fingerprint powder and lifting technique can recover and transfer latent fingerprints from human skin surfaces of dead bodies. For recovery Swedish Black powder and for transfer White Fingerprint Gelatine were used. Crime scene investigation is a process that aims at recording the scene as it is first encountered, and recognizing and collecting all physical evidence potentially relevant to the solution of the case. Crime scene investigators who have received comprehensive forensic training usually quickly take over the work at the scene and implement ideas from research institutes in practice. The personnel processing crime scenes should be aware of equipment necessary to process a crime scene and a mechanism to secure and transport the evidence to the laboratory. Physical evidence has the potential to play a critical role in the overall investigation and resolution of a suspected criminal act. We can therefore say that in investigating crimes, we are using traditional investigative approaches with modern methods and state of the art tools.

Detection of drugs in lifted cyanoacrylate-developed latent fingermarks using two laser desorption/ionisation mass spectrometric methods

This paper describes a method for lifting cyanoacrylate (CNA)-developed latent fingermarks from a glass surface and the detection of five drugs in lifted marks from fingers that had been in contact with the drugs, using Surface Assisted Laser Desorption Ionisation Time of Flight Mass Spectrometry (SALDI-TOF-MS) or Matrix Assisted Laser Desorption Ionisation TOF-MS (MALDI-TOF-MS). Two drugs of abuse (cocaine and methadone) and three therapeutic drugs (aspirin, paracetamol and caffeine) were used as contact residues. Latent fingermarks spiked with the drugs were subjected to CNA fuming followed by dusting with ARRO SupraNano™ MS black magnetic powder (SALDI-TOF-MS) or 2,5-dihydroxybenzoic acid (DHB) (MALDI-TOF-MS). The dusted mark was then exposed to solvent vapour before lifting with a commercial fingerprint lifting tape following established procedures. The presence of the drugs was then confirmed by direct analysis on the tape without further processing using SALDI- or MALDI-TOF-MS. The black magnetic fingerprint powder provided visual enhancement of the CNA-fingermark while no visual enhancement was observed for marks dusted with DHB powder. Similar [M + H](+) peaks for all the drug analytes were observed for both methods along with some sodium and potassium adducts for SALDI-MS and some major fragment ions but the SALDI signals were generally more intense. Simple exposure to acetone vapour of the CNA-developed marks enabled their effective transfer onto the tape which was crucial for subsequent MS detection of the analytes.