Analysis of patterned injuries and injury-causing instruments with forensic 3D/CAD supported photogrammetry (FPHG): an instruction manual for the documentation process.

Forensic 3D/CAD supported photogrammetry (FPHG) is a method of recording and documenting the surface of small objects, thus enabling a three-dimensional image of these objects in virtual space. With this representation on the computer screen the course of forensically relevant events can be reconstructed. The procedure allows for examining patterned injuries of skin, soft tissue or bones for matching potentially incriminated instruments in shape, size and angle.3D recording of objects to be examined requires taking series of photographs. A computer system then calculates the position in space of certain points on the surface of the objects and subsequently produces 3D data models of the objects. Using a 3D/CAD program these data models are used to generate graphic true-to-object volume models. The objects in question can then be moved against each other arbitrarily on the screen-depending on the questions to be answered-in order to compare them and possibly establish their congruence. This article covers the state of the art in FPHG procedures in the form of a step-by-step instruction. It also illustrates the wide range of FPHG applications.

Matching tire tracks on the head using forensic photogrammetry.

In the field of the documentation of forensics-relevant injuries, from the reconstructive point of view, the forensic, CAD-supported photogrammetry plays an important role; particularly so when a detailed 3-D reconstruction is vital. This is demonstrated with a soft-tissue injury to the face caused by being run over by a car tire. Since the objects (injury and surface of the tire) to be investigated will be evaluated in virtual space, they must be series photographed. These photo sequences are then evaluated with the RolleiMetric multi-image evaluation system. This system measures and calculates the spatial location of points shown in the photo sequences, and creates 3-D data models of the objects. In a 3-D CAD program, the model of the injury is then compared against the model of the possible injury-causing instrument. The validation of the forensic, CAD-supported photogrammetry, as shown by the perfect 3-D match between the tire tread and the facial injury, demonstrates how greatly this 3-D method surpasses the classic 2-D overlay method (one-to-one photography).

A study on the random distribution of a red acrylic target fibre.

This project was a target fibre study carried out by the European Fibres Group. Thirty-eight participating laboratories in nineteen countries searched four hundred and thirty five randomly selected top outer garments. The acrylonitrile/vinyl acetate co-polymer target fibre matched those in a red acrylic scarf, marketed in nine of those countries. The sales figures for the last five years were between 5- and 10,000 scarves annually. Matching fibres were found on only two garments, one fibre per garment. The possible origin of these two fibres is discussed. The result showed that the chances of finding a 'collective' of target fibres on a piece of clothing selected at random can be said to be extremely remote.

[Evaluation of cuticula structure of the human hair]. / Die Auswertung der Kutikulastruktur am Humanhaar.

The cuticula is influenced by inner and outer factors. Through the combination of these factors the cuticula takes forms, which can be individual in same cases. But in most cases the marks of the cuticula are not enough specific to attach a hair to an individual person. Therefore the hair investigation has to be done in combination with other marks of the hair.