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Polymeric fibers are one kind of trace evidence found in the crime scenes, and they play a crucial role in criminal investigation. Identification and comparison of polymeric fibers are a direct result of professional analysis. When performed properly, the analytical method used in differentiating fibers of different origins can be of high evidential value. Regular forensic examinations of synthetic fibers to determine type and subtype are based on microscopy, spectroscopy, chromatographic, and mass spectrometry. This review covers different analytical methods used in the forensic analysis and comparison of synthetic fibers.

Two-dimensional dust shoeprints are often of very high resolution and contain unique features. Lifting these prints in the most effective method may contribute much to preserving these fine details. A research was conducted by experts from Israel and Switzerland to compare gelatin lifters and electrostatic lifters for lifting shoeprints. Several substrates were chosen, and on each material a set of dry dust shoeprints was made. A set of wet prints was made on paper as well. The shoeprints were approximately of the same quality, and the only variable was the nature of the material. On substrates indifferent to the method used, the preferable sequence was tested. Gelatin lifter was superior on most substrates and for wet prints. The superior sequence for using both methods is electrostatic lifting followed by gelatin lifter.

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In recent years, there is a growing demand to fortify the scientific basis of forensic methodology. During 2016, the President's Council of Advisors on Science and Technology (PCAST) published a report that states there are no appropriate empirical studies that support the foundational validity of footwear analysis to associate shoeprints with particular shoes based on specific identifying marks, which is a basic scientific demand from the field. Furthermore, meaningful databases that can support such studies do not exist. Without such databases, statistical presentation of the comparison results cannot be fulfilled either. In this study, a database of over 13,000 randomly acquired characteristics (RACs) such as scratches, nicks, tears, and holes, as they appear on shoe sole test impressions, from nearly 400 shoe soles was collected semiautomatically. The location, orientation, and the contour of each RAC were determined for all the RACs on each test impression. The statistical algorithm Statistic Evaluation of Shoeprint Accidentals (SESA) was developed to calculate a score for finding another feature similar to a particular scanned and digitized RAC in the same shape, location, and orientation as the examined one. A correlation was found between the results of SESA and the results of real casework, strengthening our belief in the ability of SESA to assist the expert in reaching a conclusion while performing casework. The score received at the end of the process serves the expert as a guiding number, allowing more objective and accurate results and conclusions.Recently, the President's Council of Advisors on Science and Technology (PCAST) (4) published a report that went much further in the scientific demands for forensic practice and specifically for the area of shoeprints. In the words of the committee:"PCAST finds there are no appropriate empirical studies to support the foundational validity of footwear analysis to associate shoeprints with particular shoes based on specific identifying marks." ([4], p. 93).The practical way of conducting pattern comparison is well demonstrated by the shoeprint examination process. Today, shoeprints revealed at crime scenes are compared manually against suspect shoes. The first step is to determine whether the class characteristics match. These include the sole pattern, size, 1 Questioned Documents Lab, DIFS, Israel Police, 1 Bar Lev Rd., Jerusalem, 91906, Israel . 2 Toolmarks and Materials Lab, DIFS, Israel Police, 1 Bar Lev Rd., Jerusalem, 91906, Israel. 3 R&D Unit, DIFS, Israel Police, 1 Bar Lev Rd.,