“502”真空熏显手印技术的应用现状

在我国,“502”加温加湿熏显手印技术已广为普及,但“502”真空熏显手印技术人们了解很少。本文通过介绍“502”熏显手印技术的发展,着重介绍真空熏显方法的特点。     

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.     

Hydrogen cyanide and carbon monoxide in blood of convicted dead in a polyurethane combustion: a proposition for the data analysis

Carbon monoxide is a well-known toxic component in fire atmospheres. However, the importance of hydrogen cyanide as a toxic agent in fire causalities is under discussion. A tragic polyurethane mattress fire provoked death of 35 convicts in a prison (Unit I, Olmos, Penitenciary Service of Buenos Aires Province, Argentina), in 1990. There is no report of any investigation carried out with such a large amount of victims in Argentina. Carboxihemoglobin (COHb) and hydrogen cyanide (HCN) were quantified in victims blood to elucidate the cause of the death. Saturation of COHb ranged between 4 and 18%, and HCN 2.0-7.2mg/l. These latter values were higher than the lethal levels reported in literature. Other toxic components routinely measured (ethanol, methanol, aldehydes and other volatile compounds) gave negative results on the 35 cases. Neither drugs of abuse nor psychotropics were detected. Statistical chi(2) analysis was applied to find differences between HCN and COHb concentrations. Saturation of COHb and HCN in blood were not independent variables (chi(2)=8.25). Moreover, the ratio COHb/HCN was constant (0.47+/-0.04). In order to evaluate the contribution of each toxic to the diagnosis, a lethal index was defined for each toxic (LI(CO) and LI(HCN)). The most probable cause of death could be inferred by a suitable plot of both indexes. The results indicated that death in the 35 fire victims was probably caused by HCN, generated during the extensive polyurethane decomposition provoked by a rapid increase of temperature.     

Processes involved in the development of latent fingerprints using the cyanoacrylate fuming method

Chemical processes involved in the development of latent fingerprints using the cyanoacrylate fuming method have been studied. Two major types of latent prints have been investigated-clean and oily prints. Scanning electron microscopy (SEM) has been used as a tool for determining the morphology of the polymer developed separately on clean and oily prints after cyanoacrylate fuming. A correlation between the chemical composition of an aged latent fingerprint, prior to development, and the quality of a developed fingerprint has been observed in the morphology. The moisture in the print prior to fuming has been found to be more important than the moisture in the air during fuming for the development of a useful latent print. In addition, the amount of time required to develop a high quality latent print has been found to be within 2 min. The cyanoacrylate polymerization process is extremely rapid. When heat is used to accelerate the fuming process, typically a period of 2 min is required to develop the print. The optimum development time depends upon the concentration of cyanoacrylate vapors within the enclosure.     

彩色背景客体上手印的显现方法

目的利用真空金属镀膜法和＂502＂胶熏显法之间的空间互补性原理,考察显现杂色背景客体表面潜手印过程中遇到的杂色背景干扰问题。方法对杂色背景客体表面的同一枚手印分别采用紫外照相、＂502＂胶熏显、真空镀膜方法处理,比较去除背景干扰能力。结果采用＂502＂胶熏显,真空金属镀膜后期增强处理,能够使指纹纹线清晰连贯,并能有效消除背景杂色干扰。结论该方法可有效消除背景杂色干扰,清晰显现有彩色背景的易拉罐、照片纸等客体上的指纹。     

Inter-species variation in bone mineral behavior upon heating

The characterization of inter-species variation in bone mineral (b-HAP) is of relevance to forensic science and archaeology, but has not previously been widely explored. Results of an investigation into unheated bone mineral and behavior of bone upon heating for 12 animal species (including human) demonstrate that b-HAP characteristics, quantitatively measured using X-ray diffraction (XRD) analysis, exhibit significant inter-species variation. Human bone was found to be significantly different to all other species in terms of b-HAP lattice parameter values from unheated and heated bone and in terms of recrystallization behavior of b-HAP upon heating bone to 600°C. The amounts of b-HAP thermal decomposition products were also significantly different for human bone heated to 1400°C compared to those obtained for most other species. Therefore, there is potential for the development of an XRD-based method of species identification, particularly one that distinguishes human from non-human bone.     

Cyanide and amygdalin as indicators of the presence of bitter almonds in imported raw almonds

Abstract: Consumer complaints received by the U.S. Food and Drug Administration in August 2010 about raw organic almonds tasting “bitter” opened an investigation into the presence of bitter almonds in the imported product. Bitter almonds (Prunus amygdalus) contain the cyanogenic glucoside amygdalin, which hydrolyzes to produce cyanide. Ultraviolet–visible spectrophotometry was used to detect and quantitate cyanide, and liquid chromatography‐mass spectrometry was utilized to detect amygdalin in the submitted samples. Control bitter almonds were found to contain 1.4 mg cyanide/g and an estimated level of 20–25 mg amygdalin/g. The questioned samples contained between 14 and 42 μg cyanide/g and were positive for the presence of amygdalin. Sweet almonds were found to be negative for both compounds, at levels of detection of 4 μg cyanide/g and 200 μg amygdalin/g.     

运用“502”粘合剂显现长时间潜在手印的研究及应用

本文对“502”粘合剂显现手印法进行适当的技术改进,通过显现一起潜在手印遗留时间长达一年以上罕见案例的实际应用,并对操作方法和影响因素等方面进行讨论,以拓宽“502”粘合剂显现潜在手印的应用范围.     

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.     

Immunolabeling and the compatibility with a variety of fingermark development techniques

Much information can be obtained from the chemical composition of a fingermark, which can be helpful in crime scene investigation. Immunolabeling can be used to extract information about the donor of the fingermark and it can also act as a fingermark development tool in sequence with the standard fingermark development techniques. However, before immunolabeling can be used in forensic practice more information on the possibilities and limitations of this technique is required. In this study, our aim was to investigate if immunolabeling is compatible with standard development protocols (indanedione-zinc, indanedione-zinc followed by ninhydrin spraying, physical developer, cyanoacrylate fuming, cyanoacrylate followed by basic yellow staining, lumicyanoacrylate fuming and polycyanoacrylate fuming). Immunolabeling was carried out successfully on all developed fingermarks, whereby dermcidin was selected as antigen of interest. We can conclude that immunolabeling is compatible with a wide variety of different fingermark developers. This finding in combination with previous findings, makes immunolabeling an interesting technique, which can be of great value in the forensic field.     

An investigation into the use of a portable cyanoacrylate fuming system (SUPERfume®) and aluminum powder for the development of latent fingermarks

Abstract: Few techniques offer “in situ” methods of friction ridge skin mark development. “In situ” development reduces mark transportation, degradation, and often cost. The effectiveness of cyanoacrylate fuming using the SUPERfume^® and dusting with aluminum powder for latent fingermark development on several nonporous surfaces, stored in various temperature environments for time periods up to 52 weeks, was investigated. Five thousand and four hundred latent fingermarks were deposited under controlled conditions and graded. The results suggested that cyanoacrylate fuming (SUPERfume^®, Foster and Freeman, U.K.) was more effective at developing latent fingermarks on textured and smooth plastic surfaces and for marks stored in temperatures of 37°C, whereas aluminum powder was more effective on glass, enameled metal paint, and varnished wood, and for storage temperatures below 20°C. There were no significant benefits to using either technique for marks older than 24 h, but it was possible to develop fingermarks following 52 weeks of storage using both techniques.     

Development of a finger printing device for use on a mobile robot

In this paper, we describe the development of a device for fuming fingerprints with cyanoacrylate (Super Glue) to enable police tactical units to obtain fingerprint evidence from suspicious packages using a remote-controlled robot. Through a series of initial experiments and preliminary designs, we show that effective cyanoacylate fuming requires sufficient heat, humidity, and airflow. This work led to the development of a final working prototype, called robot accessory for fuming fingerprint evidence (RAFFE), which is currently being field tested by the Calgary Police Service.     

Development of Latent Fingermarks on Surfaces of Food‐A More Realistic Approach

Latent fingermark developing methods from food (mandarin, egg, banana, apple, potato, carrot, eggplant, onion, bell pepper, and tomato) surface has been studied by 10 methods, including powdering method, small particle reagent method, and cyanoacrylate fuming method. The foods were stored under two conditions (room temperature and refrigerator) before fingermark deposition and aged for 2, 24, 48, and 72 h before fingermark development. In most of the food surfaces used in this study, cyanoacrylate fuming with 80% relative humidity was superior to the powder or small particle reagent methods. The quality of the fingermarks varied depending on the storage conditions before the fingermark deposition (in the refrigerator or at ambient temperature) and the time elapsed since the fingermark deposition. However, the storage conditions before the fingermark deposition and the time elapsed since the fingermark deposition did not show any correlation with the quality of the fingermark.     

A 'cyanoacrylate case' for developing fingerprints in cars.

A portable case has been developed by which cyanoacrylate (super glue) fuming can be used inside a vehicle suspected of being involved in serious crime. The car itself serves as a fumigation chamber and the cyanoacrylate vapours are fed into the car via a hose. Connected to the hose and suspended inside the car is a vapour diffuser. The cyanoacrylate originates from a portable case where there is a sealed heater and also a command panel with hygrometer and thermometer for a technician to control the process. There is also space inside the case for other necessary equipment.     

新型荧光502粉末与502胶＋荧光染色显现潜在手印的比较

目的对新型荧光502粉末显现非渗透性光滑客体表面潜手印的一步荧光502显现新技术和传统502胶水熏显＋荧光染料染色显现手印技术进行比较研究。方法比较实验研究,对荧光502粉末和502胶水使用同一自动熏显柜先后进行熏显,荧光502粉末熏显结束后直接在蓝光灯下激发进行观察和拍照;502胶水在熏显完成和聚合物完全固化后使用罗丹明6G和BBD溶液进行荧光染色,再进行光致荧光照相。结果一步熏显和二次染色的显现效果基本相同,但两者的显现效果也因检材性质和遗留时间的不同而存在一些差别。结论新型荧光502粉末可以作为一种显现非渗透性光滑客体表面上潜手印的常用方法,尽管新方法对某些客体的显现效果并不好,但对大多数客体来说,其显现效果并不弱于二次染色的方法,并且使用新型荧光502粉末进行一步熏显不会引入有机溶剂,不会引起502聚合物的溶解或造成破坏,确保了纹线及其细节特征不被损坏,也避免了染色后因漂洗不当使手印纹线被冲掉的可能,还不会破坏脱落细胞等生物检材。     

Effects of Cyanoacrylate Fuming,Time After Recovery,and Location of Biological Material on the Recovery and Analysis of DNA from Post‐Blast Pipe Bomb Fragments*

Abstract: This study investigated the effects of time, cyanoacrylate fuming, and location of the biological material on DNA analysis of post‐blast pipe bomb fragments. Multiple aliquots of a cell suspension (prepared by soaking buccal swabs in water) were deposited on components of the devices prior to assembly. The pipe bombs were then deflagrated and the fragments recovered. Fragments from half of the devices were cyanoacrylate fumed. The cell spots on the fragments were swabbed and polymerase chain reaction/short tandem repeat analysis was performed 1 week and 3 months after deflagration. A significant decrease in the amount of DNA recovered was observed between samples collected and analyzed within 1 week compared with the samples collected and analyzed 3 months after deflagration. Cyanoacrylate fuming did not have a measurable effect on the success of the DNA analysis at either time point. Greater quantities of DNA were recovered from the pipe nipples than the end caps. Undeflagrated controls showed that the majority (>95%) of the DNA deposited on the devices was not recovered at a week or 3 months.     

Cyanide quantification in post-mortem biological matrices by headspace GC-MS

Cyanide is a powerful chemical asphyxiant found in some forensic cases following voluntary (suicide) or involuntary ingestion (fire, accidental exposure). A quantification method for cyanide that is specifically suited to post-mortem forensic purposes was developed. Determination was performed by headspace gas chromatography coupled to mass spectrometry using a GS-GASPRO column on an HP-6890 gas chromatograph with an HP-5973N mass detector. The biological sample was treated with an internal standard, frozen, glacial acetic acid was added and the sample was then incubated at 60°C for 15min. The headspace was sampled with a disposable syringe, and analyzed to quantify hydrogen cyanide. Isotopically labeled cyanide ((13)C(15)N) was used as the internal standard to minimize matrix effect and sampling error. The method produced an extended linear dynamic range (0.07-50μg/mL), and a method detection limit of 0.02μg/mL. Identical calibration curves were obtained when blood, gastric contents and aqueous solutions were used as the calibration standard matrix. This method was also successful in quantitating cyanide in gastric contents, one of the most variable biological fluids. The method has been validated and is being used for current forensic cases such as fire victims and suicides.     

Identification of a Suspect in a Murder Case through Recovery of Fingermarks from a Fired Cartridge Case

During the period of one year, the Police of the State of Espírito Santo in Brazil analyzed 1,431 cartridge cases obtained from crime scenes and seizures. The cartridges were subjected to a development sequence (cyanoacrylate fuming + gun bluing + fluorescent dying), and panoramic images of the developed fingermarks were generated based on the photographs taken during the rotation of the cartridges. Ridge details were observed in 50 cartridges, but only in 5 cartridges, the marks were considered with value for identification. The fingermarks were searched in the Automated Fingerprint Identification System (AFIS) of the Brazilian Federal Police and, in one case, it was possible to obtain the suspect's identification. In our knowledge, this is the first case in Brazil of identification of a suspect based on a fingermark recovered from a fired cartridge case.     

In vitro production of GHB in blood and serum samples under various storage conditions

The in vitro production of GHB was observed in freshly collected, untreated whole blood samples using glass BD-Vacutainers and polypropylene S-monovettes. GHB concentrations were determined daily over a period of one week and after 3, 6 and 9 weeks again. Furthermore, the GHB concentration in 40 untreated random whole blood samples stored at 4°C for a longer period of time (10 samples 12 month, 10 samples 24 month and 20 samples 36 month) was also determined. For comparison, the in vitro production of GHB in freshly collected and prepared serum samples was observed. GHB serum concentrations were determined three times over a period of one week and once again after six weeks. Sample preparation was performed by means of methanolic extraction following the precipitation of whole blood and serum samples. A methanolic standard calibration was done in a low range of 0.005-0.1 μg/mL (LOD: 0.004, LLOQ: 0.013). For quantification a spiked blood bank serum with a determined GHB concentration of 0.09 μg/mL was used. Corrected calibrations in the range of 0.09-5.09 μg/mL were used (LOD: 0.08 μg/mL, LLOQ: 0.30 μg/mL), recovery: 91.3% (high level: 4.09 μg/mL) 50.5% (low level: 0.19 μg/mL). RESULTS: Relevant elevation of GHB was observed in all whole blood samples stored in liquid form (4°C or room temperature). In two of the 40 whole blood samples stored over a longer period of time at 4°C, GHB concentrations in the range of 13 μg/mL were even determined. These findings constitute grounds for caution. Even a GHB cut-off level of 5 μg/mL cannot be considered as "absolutely positive" proof of a case of exogenous administration, at least in untreated liquid blood samples in long time storage. However, no significant elevations of GHB were otherwise observed in any of the serum samples independently of storage temperature nor in the whole blood samples that were frozen for storage. CONCLUSIONS: The results suggest that the cut-off for exogenous GHB of 5 μg/mL could be lowered significantly, with the consequence of winning valuable time for the potential victim, but only if serum is collected for GHB determination or if the whole blood sample is frozen immediately after collection and the procedure well documented.     

Fingermark visualisation on metal surfaces: An initial investigation of the influence of surface condition on process effectiveness

Fingermark recovery from metal surfaces is an area of operational interest, both from the association of metals with weapons used in violent crime and from the increasing incidence in metal theft. This paper reports a feasibility study into the effectiveness of a range of fingermark visualisation processes in developing fingermarks on clean metals (brass, bronze and stainless steel), and on the same metals after prolonged exposure to an outdoor environment. Scanning electron microscopy (SEM) was used to investigate how the surface type and condition could influence the development of fingermarks for each of the processes used. It was found that the behaviour observed varied between each of the processes (cyanoacrylate fuming, Lumicyano?, gun blueing and carbon-based powder suspension). In some cases the chemical composition of the surface affected the development of the mark more than the surface condition, and in other cases the reverse was true. The best performing processes differed according to the surface type and condition, with cyanoacrylate fuming processes working best on brass and bronze, and powder suspensions being better on stainless steel. These preliminary results reinforce the need to take into account both surface type and condition before selection of the most effective fingermark visualisation process and demonstrate the value of techniques such as SEM in developing a fundamental understanding of the interactions between fingermarks and surfaces.