Marcel de Puit's Quick Files

The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

Fingerprint Development Techniques: Theory and Application

A comprehensive review of the latest fingerprint development and imaging techniques

Surface Analysis Techniques in Forensic Science: Successes, Challenges, and Opportunities for Operational Deployment

Surface analysis techniques have rapidly evolved in the last decade. Some of these are already routinely used in forensics, such as for the detection of gunshot residue or for glass analysis. Some surface analysis approaches are attractive for their portability to the crime scene. Others can be very helpful in forensic laboratories owing to their high spatial resolution, analyte coverage, speed, and specificity. Despite this, many proposed applications of the techniques have not yet led to operational deployment. Here, we explore the application of these techniques to the most important traces commonly found in forensic casework. We highlight where there is potential to add value and outline the progress that is needed to achieve operational deployment. We consider within the scope of this review surface mass spectrometry, surface spectroscopy, and surface X-ray spectrometry. We show how these tools show great promise for the analysis of fingerprints, hair, drugs, explosives, and microtraces. Expected final online publication date for theVolume 15 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates

Analysis of amino acid enantiomers from aged fingerprints

Fingerprints found at a crime scene can be key in criminal investigations. A method to accurately determine the age of the fingerprint, potentially crucial to linking the fingerprint to the crime, is not available at the moment. In this paper, we show that the use of the enantiomeric ratio of d/l-serine in fingerprints could pose as interesting target for age estimation techniques. We developed a UPLC-MS/MS method to determine the enantiomer ratios of histidine, serine, threonine, alanine, proline, methionine and valine from fingerprint residue. We found a significant change only in the relative ratio of d-serine with increasing fingerprint age after analysis of fingerprints up to 6 months old

Amino acid profiling from fingerprints: using Amide Stationary-Phase UPLC-MS

UPLC-MS is a commonly used technique to first separate complex samples and subsequently quantify molecules of interest. Herein we describe the use of UPLC-MS using an amide stationary phase to quantify non-derivatized amino acids extracted from fingerprints. As detector either a triple-quadrupole MS/MS or a TOF-MS detector was used. This method allows for a simple and fast sample preparation, which facilitates the analysis of large amounts of samples

The evaluation of fingermarks given activity level propositions

Fingermarks are highly relevant in criminal investigations for individualization purposes. In some cases, the question in court changes from ‘Who is the source of the fingermarks?’ to ‘How did the fingermark end up on the surface?’. In this paper, we explore evaluation of fingermarks given activity level propositions by using Bayesian networks. The variables that provide information on activity level questions for fingermarks are identified and their current state of knowledge with regards to fingermarks is discussed. We identified the variables transfer, persistency, recovery, background fingermarks, location of the fingermarks, direction of the fingermarks, the area of friction ridge skin that left the mark and pressure distortions as variables that may provide information on how a fingermark ended up on a surface. Using three case examples, we show how Bayesian networks can be used for the evaluation of fingermarks given activity level propositions

Using case specific experiments to evaluate fingermarks on knives given activity level propositions

Bayesian networks have shown to be a useful tool for the evaluation of forensic findings given activity level propositions. In this paper, we demonstrate how case specific experiments can be used to assign probabilities to the states of the nodes of a Bayesian network for the evaluation of fingermarks given activity level propositions. The transfer, persistence and recovery of fingermarks on knives is studied in experiments where a knife is either used to stab a victim or to cut food, representing the activities that were disputed in the case of the murder of Meredith Kercher. Two Bayesian networks are constructed, exploring the effect of different uses of the experimental data by assigning the probabilities based on the results of the experiments. The evaluation of the findings using the Bayesian networks demonstrates the potential for fingermarks in addressing activity level propositions

Visualisation of amphetamine contamination in fingerprints using TOF-SIMS technique

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was applied to detect traces of amphetamine on fingerprints. In the present study, three different lift tapes and latent powder fingerprints were tested. The obtained results show that it is possible to identify traces of a drug as well as its distribution over the tested fingerprint after its transfer from the primary base onto an adhesive lifter (secondary base). Moreover, images obtained by the TOF-SIMS technique enable the observation of very small areas of the analysed fingerprint as well as the identification of micro-objects (residues of a contaminant) that were left on the fingerprint. The use of the black latent fingerprint powder did not interfere with the TOF-SIMS analysis, which makes it possible to effectively use this technique to study the traces of substances on the revealed fingerprints