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This technical note describes in detail a method for associating individual sheets of blank A4 white paper from the same ream by the physical fit of machine‐cut edges. A large‐scale laboratory trial involving ~700 sheets of paper from 24 different reams (plus one spoiled sample), and more than 20,000 potential physical fits, correctly associated and sequenced 219 pairs of sheets together with a 100% empirical success rate and no false associations. The edge profile of each short machine‐cut end of a sheet of A4 paper allows us to physically fit sheets of paper from the same ream to each other and use this to predict the sequence of sheets in a set of documents. In a real‐life scenario, it may now be possible to detect the substitution or addition of a sheet in a multipage document, link documents from different sources to each other or to a common source of paper (e.g. to paper from a seized printer or from an accused's address) or to date documents. The study provides data for the application of this method in forensic casework and supports the practitioner when forming conclusions in this type of case. [ABSTRACT FROM AUTHOR]

The absolute dating of documents is still one of the most important challenges for forensic document examiners (FDE). The potential difference between the date on a questioned document and the actual year of production of the used paper can be only 1 to 5 years. Until now, there was no analytical method with this accuracy available. This study demonstrates a method for an absolute dating of paper by using the 14C bomb peak and dating the starch in the paper. Accelerator mass spectroscopy (AMS) radiocarbon measurements were performed on starch extracts and cellulose fibers from 50 paper samples with known production year from 1950 to 2018. For most of the paper samples, the measured 14C concentration values in the starch extracts were highly correlated with the data of the 14C bomb peak calibration curve. The differences between the calibrated ages and the actual harvest years of the starch‐containing plants were only up to 3 years. The 14C concentration in the paper fibers showed a lower but significant correlation with the production year of the papers and can be used to support the dating results of the starch extracts. In order to secure the accuracy of the dating, aside from the radiocarbon measurements of the extracted starch other analytical methods or data are used, like a detailed chemical analysis of the paper composition including fiber composition and the spectroscopic analysis of the purity of the starch extracts. In practice, only starch extracts without contaminations are used for the paper dating. [ABSTRACT FROM AUTHOR]

Paper evidence usually undergoes two consecutive examinations in forensic laboratories: ESDA (electrostatic detection apparatus) to detect indented impressions and a subsequent search for fingermarks by optical, physical, and chemical techniques. The ability of ESDA in visualizing fingermarks is well known. The aim of the present study is to understand better how long fingermarks can be developed with ESDA and if the different constituents of fingermarks show a different susceptibility to being developed. Several types of marks were collected from six donors on A4 standard office copy paper and tested with ESDA up to 69 days from deposition. A clear difference between natural, eccrine, and sebaceous marks emerged, being the latter ones better developed. ESDA developed standard sebaceous marks up to 16 days from deposition, whereas natural marks were visible within a few days. Eccrine marks were mainly visualized in reverse mode, despite the quality of these marks was not as good as the sebaceous marks. The appearance of the mark (standard/reverse) seemed to be correlated with time since deposition. Data suggest that the mechanism by which ESDA visualizes the fingermarks could be related to the residue (water‐soluble and/or non‐water‐soluble) available on the surface of the substrate and not yet absorbed by the paper. ESDA could act as a useful screening tool in fingermark visualization on porous surfaces, especially because it is a non‐destructive technique. Therefore, as a general procedure, it is highly recommended to acquire potential fingermarks developed by means of ESDA before proceeding with fingermark visualization. [ABSTRACT FROM AUTHOR]

Abstract: Previously unreported line patterns visible under ultraviolet light were observed on a proportion of plain white A4 printer/copier paper from different manufacturers. These Ultraviolet Line Patterns (UVLPs) usually appear as stripes down the vertical length of the paper. Typically, the UVLPs were found to “repeat” through the ream in a predictable way, while also changing. It is postulated that the repeating nature of the UVLPs is a result of the way that paper is manufactured. This leads to the ability to sequence the sheets compared to their original source paper. Even in the absence of UVLPs, it is possible to use our observation of the manufacturing process to anticipate the order of several sheets of paper and conclusively associate them, in some cases, by physically fitting their machine cut edges and crossing paper fibers. Such a novel approach to examining questioned documents would be highly useful in forensic casework. [ABSTRACT FROM AUTHOR]

Polyvinylpyrrolidone (PVP) has been used in combination with 1,2-indanedione (1,2-IND) and ZnCl2 (Zn) to develop latent fingermarks. The results show that the optimal ratio of 1,2-IND/Zn:PVP is 1.0:0.4 (the concentration of PVP is 8%) for developing fingermark. The developed formulation was tested on the surfaces of 12 kinds of thermal papers. The variation in the fingermark development efficiency was observed within the same and among different kinds of thermal papers. The fingermark development efficiency was mostly better on the thermally sensitive surface compared to the thermally nonsensitive surface. However, similar or even better development was observed from a few thermally nonsensitive surfaces. The present method has shown better efficiency compared to the three other proposed methods on the thermally sensitive surface. In contrast, the present method was proven not the best for the thermally nonsensitive surface. [ABSTRACT FROM AUTHOR]

Evaluation of paper brightness in multipage documents is a practice of forensic document examiners when there is a question of a page insertion or substitution. This article demonstrates that occasional errors occur in the manufacturing process that affects the consistency of paper brightness. The inconsistency of paper brightness may therefore influence conclusions reached in authenticating documents. Reams of multipurpose paper, from 21 manufacturers, were examined. When assessing the individual pages of each package with an ultraviolet light, approximately 30% of the reams revealed differences in paper brightness. A study of the paper-manufacturing process was conducted to determine where variations originate. It is concluded that brightness differences occur when one incompatible roll of paper is mistakenly placed with others used for one production run. It was also determined that brightness variations (when present) are patterned throughout individual reams. When the authenticity of a document is in question, consideration of these findings is essential to assure an accurate assessment. [ABSTRACT FROM AUTHOR]

Although the ability to develop latent fingerprints on paper using heat alone has been noted previously, it has been considered impractical for casework and inferior to other techniques. Here a new refinement of the technique is demonstrated for the high quality development of latent fingerprints on porous surfaces such as paper. Fingerprints deposited on various papers were developed by exposing them to hot air with a temperature in the vicinity of 300°C, for periods of c. 10–20 sec. Several different heating methods were tested. The novel observation was made that after shorter heating times, fluorescent prints could be observed. These became visible after longer heating times, as noted by earlier workers, but with greatly improved contrast compared with their results. Prints from various donors (and aged prints) were developed with excellent ridge contrast. Direct heating methods (such as with a hot plate or press) produced inferior results. The refined technique, which is simple, safe and inexpensive compared with conventional methods, has great potential for use in forensic laboratories. [ABSTRACT FROM AUTHOR]