Use of liquid nitrogen to remove duct tape from a homicide victim.

Removal of duct tape or similar adhesive products from a homicide victim may be facilitated by rapidly chilling the tape surface with liquid nitrogen. Physical separation of tape layers can be performed using the same technique. Cyanoacrylate glue (i.e., "super-glue") may be used to preserve fingerprints on the outer surface of the tape for recovery, or other techniques may be used to recover fingerprints from the outer surface prior to tape removal.     

An unusual mechanical asphyxia in a homicide-suicide case by smothering and strangulation

A very unusual homicide of 2 children by smothering and strangulation by means of a rubber adhesive band carried out by the mother who committed suicide by the same manner is presented. Smothering is supposed to be one major cause of death in child homicide. Suicide by smothering is relatively uncommon. Suicidal smothering by winding strips of adhesive tape around the head to cover the nose and mouth is an even rarer method recently described in literature. The circumstances of the crime and the macroscopic and microscopic evidence are discussed to reduce the potential for underdiagnoses or mistakes in such cases in which it may be difficult to establish whether suicide or homicide occurred.     

Autopsy Reenactment – A Useful Technique in the Evaluation of Adhesive Tape Asphyxia

A 19‐year‐old woman was found dead with her face and head wrapped in plastic adhesive tape in a cupboard beside an opened helium cylinder. Despite the alleged presence of a suicide message on a social networking website, the unusual circumstances raised the possibility at the time of autopsy of either accidental death from sexual asphyxia or homicide. A carefully monitored reenactment demonstrated, however, that the type of commercial adhesive tape that had been used did not cause complete airway obstruction and that it was possible to wrap a considerable length of tape around the head and neck with the breath held. All of the features at autopsy were, therefore, compatible with self‐infliction. Asphyxial death was attributed to the combined effects of smothering from tape and anoxia from helium, an extremely rare combination in young females.     

Medicolegal aspects of witnessed suicide due to gunshot to the head. II. Legal medicine aspects and examination of the firing hand

The second part of the paper on suicides by gunshots to the head in the presence of witnesses focuses on relevant morphological autopsy findings such as entrance site, signs of close range or contact shots, bullet path etc. and also discusses selected aspects of ascertaining gunshot residues. For the identification of the shooter an integral medicolegal assessment of all the facts including the investigation results and the autopsy findings is essential. However, the morphological findings alone do not allow safe diagnosis, as for example in a homicide the temporal region, which was affected in all our cases, may have been deliberately chosen by the perpetrator as a localization typical of suicide. Thus methods to ascertain gunshot residues on the firing hand (by means of adhesive films and the polyvinyl-alcohol collection method--PVAL) are of great practical importance. In seven cases adhesive films and/or the polyvinyl-alcohol collection method were used. In one case the gunshot residues (GSR) were analysed by means of tape lifts and subsequent scanning electron microscopy (SEM). It was found that especially the combined application of topographical (adhesive tape/PVAL) and cumulative (SEM) methods allowed for the doubtless identification of the shooter, thus usually confirming the suicide. By the example of one case it is demonstrated that without the immediate collection of evidence at the scene objective reconstruction of the event becomes impossible. On the basis of the reported cases recommendations are finally given for a differentiated approach in the medicolegal evaluation of alleged witnessed suicide by gunshot (to the head).     

Chemical fingerprinting of adhesive tapes by GCMS detection of petroleum hydrocarbon products

Pressure-sensitive adhesive tapes often represent key evidence of crimes such as assault, rape or homicide; thus, the development of analytical techniques able to contribute to a detailed characterization of these materials is of forensic importance. The gas chromatography-mass spectrometry (GCMS) analysis of the solvent extractable fractions of a suite of electrical and gaffer adhesive tapes spanning a range of colors and manufacturers identified a number of petroleum-derived hydrocarbons. Molecular and isotopic analyses of hydrocarbon constituents of complex materials have found wide analytical utility including the forensic investigation of oil spills and arson. Here, we investigate the utility of these techniques for characterizing the hydrocarbon composition of pressure-sensitive adhesive tapes for forensic correlation purposes. Subtle distinction of tape samples was evident in the GCMS distribution of several hydrocarbon groups including alkyl-naphthalenes, hopane and sterane biomarkers. Linear discriminant analysis of the abundances of these products provided high level differentiation of tape manufacturer. The distinction of different adhesive tape samples was further extended by measurement of their stable carbon isotopic values. The molecular and isotopic differences of the petroleum content of tapes are consistent with the use of different petroleum materials used in the manufacturing process and demonstrate the benefits of the combined use of complementary oil hydrocarbon characterization approaches. This study reveals the forensic potential of using established petroleum characterization methods for characterizing materials with a petroleum-derived hydrocarbon element.     

Applicability of DNA analysis on adhesive tape in forensic casework

Adhesive tape is commonly used in crimes and is often the subject of forensic evaluation. DNA analysis of adhesive tape can provide DNA profiles of suspects. The object of this study was to evaluate the applicability of DNA analysis on adhesive tape samples in forensic casework. We retrospectively reviewed all cases involving adhesive tape or similar items received by our institute for DNA analysis during the past 11 years. From 100 forensic cases reviewed, 150 adhesive tape samples were examined. A total of 98 DNA profiles were obtained from these samples. Sixty-two of the profiles provided feasible case-relevant information. In conclusion, DNA profiling of adhesive tape samples can be useful in a variety of forensic cases.     

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.     

Selection of an adhesive tape suitable for forensic fiber sampling

Five commercial adhesive tapes were tested for fiber uptake and saturation, for recovery and for ease of analysis. On the basis of the results, a high tack adhesive tape has been selected to be used for forensic fiber sampling. This adhesive tape is used as sampling material in two different micro trace kits. The first tape lifting kit is used mainly for the sampling of cars and the second is a 1:1 tape lifting kit for the collection of fibers on a corpse.     

胶带的红外光谱检验

目的建立胶带的种类检验、方法。方法应用傅利叶显微红外光谱仪,分别对胶带的胶质、基质(基材)及整体(胶质和基质同时存在)进行检测分析。结果不同种类胶带,红外吸收图谱存在差异,相互间图谱匹配率不同。通过比对分析,可对不同种类的胶带进行鉴别。结论该方法检验胶粘带(胶带),检材用量少、结果准确,操作简便,具有很强的实用性。     

Identification and Comparison of Electrical Tapes Using Instrumental and Statistical Techniques: II. Organic Composition of the Tape Backing and Adhesive*

Abstract: The microtexture and elemental composition of the backing of electrical tapes have been shown to be highly discriminating. In this study, the organic composition of electrical tape was evaluated as a complementary means of distinguishing tape brands. The backing and adhesive of 72 rolls of electrical tape were analyzed via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FTIR) and discriminant analysis was used to classify all samples by brand. Generally, the accuracy for FTIR data (88–99%) was higher than that for elemental data (86–94%). FTIR spectra from the adhesive layer were the most discriminating. In separate studies, two fragments of blast-damaged tape were correctly assigned to their brand of origin and discriminant analysis was used to quantitatively associate or exclude tape samples from two bombing cases.     

Analysis of pressure sensitive adhesive tape: I. Evaluation of infrared ATR accessory advances

Attenuated total reflection (ATR), also known as internal reflection spectroscopy (IRS), is a forensically accepted method for infrared (IR) analysis of pressure sensitive adhesive tapes. Advancements of ATR accessories in the last decade have provided the forensic examiner several ATR methods to choose from. These accessories offer a variety of ATR crystal choices with a variety of prices and capabilities. Four different types of pressure sensitive adhesive tapes including duct tape, electrical tape, packaging tape and office tape have been used to compare six different ATR methods. Each of the methods tested offers both benefits and limitaltions which must be considered for the type of sample to be analyze. The intent of this paper is to assist the reader in better understanding ATR techniques, the many differences among currently available ATR accessories and how the method is applied to the analysis of pressure sensitive adhesive 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.     

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。     

Unusual suicidal smothering by means of multiple loops of adhesive gummed tape

In suicidal asphyxia smothering is very rare, especially when caused by winding strips of adhesive tape around the head to cover the nose and mouth. The authors report a very unusual case in which the deceased, a 66-year-old man, was found with two strips of tape wound around his head: the first, more superficial tape was wrapped six times and the second was wrapped nine times. Only integration of the crime scene data with those of the autopsy and the patient's psychological profile enabled identification of the event as suicide.     

A single approach to the recovery of DNA and firearm discharge residue evidence.

The Laboratory of the Strathclyde Police Forensic Support Department extracts DNA from cellular material recovered from garments submitted as evidence. The standard method used an adhesive tape attached to a plastic or acetate support. This paper demonstrates a method whereby a single sample, recovered from clothing, can be examined for Firearm Discharge Residue and then extracted for DNA.     

Paint and tape: collection and storage of microtraces of paint in adhesive tape

The collection and preservation of microtrace evidence with the aid of an adhesive tape is a method of choice in forensic science. This technique is rapid and easy and allows the concentration of microtraces on a carrier, which facilitates further investigations in the laboratory. Adhesive tapes are currently used to secure microtraces of fibers and glass, but hardly for traces of automotive paint and other lacquers for fear of interference with the analysis of binders. A collection of automotive paint consisting of original and repair lacquers collected by tape has been evaluated. After various times of storage within the tape, these samples were compared with untreated references by microscope FT-IR and microspectrophotometry (MSP). Another set of paints was collected in 1984, stored within the tape until 1995, and examined the same way. About 170 layers of lacquer with various types of binder were examined. With the exception of one clear lacquer no difference between treated samples and references was detected. This small difference observed could be correlated to the exposure to xylene (extractant) and was not caused by the storage within the adhesive tape.     

Identification of pressure-sensitive adhesive polypropylene tape

Identification of colorless, transparent, pressure-sensitive adhesive polypropylene tape (PP tape) was performed using infrared absorption spectrometry (IR) and pyrolysis gas chromatography mass spectrometry (Py-GC/MS) to determine the pressure-sensitive adhesive. Twenty different products of colorless, transparent PP tapes were examined in this study, and the results of analysis of IR spectra and Py-GC/MS were classified into twelve groups. In addition, the tapes were classified into 14 groups on the basis of IR measurement of release agent present in the backside. The results indicate that colorless, transparent PP tapes can be distinguished in terms of manufacturer, thereby demonstrating that this method of identifying colorless, transparent PP tape is effective. Moreover, the method was applied to the analysis of an actual forensic sample.     

The Use of Adhesive Tape for Recovery of DNA from Crime Scene Items

Abstract: The selection of the appropriate method of collection of biological material from crime scene items can be crucial to obtaining a DNA profile. The three techniques commonly used for sampling items are: cutting, swabbing, and taping. The tape sampling technique offers an advantage, in that it enables the collection of a potentially highly informative source of DNA, shed epithelial cells, from selected areas on crime scene items (the inside fingers of a glove, for instance). Furthermore, surface collection of biological material by taping reduces co‐sampling of known PCR inhibitors such as clothing dyes. The correct choice of tape for crime scene item sampling is important. Not all tapes are suitable for biological trace evidence collection as well as DNA extraction. We report on one tape that met both these criteria. Three different cases are presented which demonstrate the usefulness of adhesive tape sampling of crime items. Finally, the advantages of the tape collection technique are discussed and guidelines for preferred areas of tape sampling on various casework items are presented.     

故意杀人罪的手段残忍及其死刑裁量——以刑事指导案例为对象的研究

故意杀人罪在死刑适用案件中占有较大比重，其死刑裁量对于减少和控制死刑具有重要意义。而手段残忍是司法实践中故意杀人罪死刑裁量的重要因素，并且独立于故意杀人罪的情节严重、情节恶劣以及后果严重等评价性用语。通过对十个被司法机关认定为故意杀人手段残忍的典型案例的探讨，可以认为故意杀人罪的手段残忍是指，在杀人过程中，故意折磨被害人，致使被害人死亡之前处于肉体与精神的痛苦状态。司法实践中存在着将故意杀人罪的手段残忍与情节严重、情节恶劣以及后果严重等评价性用语相混淆的现象，致使故意杀人罪的手段残忍内容宽泛，沦为一句法律套语。故意杀人罪的死刑裁量应当主要从案件性质、犯罪情节、犯罪后果、主观恶性和人身危险性等四个方面进行考量。     

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.