Manufacturing of firearms parts: relevant sources of information and contribution in a forensic context

In the context of forensic cases involving firearms, a major issue to address is the identification of the firearm used to discharge questioned elements of ammunition – bullets or cartridge cases – found during the scene investigation. When a questioned firearm is available, reference bullets and cartridge cases are produced through controlled test-fires. The marks left on both the questioned and reference elements of ammunition are analysed before being compared. The processes used to manufacture the firearms tend to influence the type and frequency of some of these marks. Knowing how the questioned firearm was produced is a key element to identify the relevant marks for comparison purposes. Finding this information can be challenging, as it is not necessarily publicly available. After presenting the manufacturing processes used to produce the main parts of firearms in contact with the elements of ammunition, this review includes an updated list of processes used by specific manufacturers, relying not only on the literature. The results highlight the necessity to consider a wide range of sources when gathering information about the manufacturing processes. Apart from general and specialized forensic literature, the online content made available by the manufacturers themselves is also a valuable complementary source of information. Contacting the manufacturers or visiting their premises is sometimes necessary to understand the full extent of the processes and how they can influence the marks of forensic interest

Buying drugs on a Darknet market: A better deal? Studying the online illicit drug market through the analysis of digital, physical and chemical data.

Darknet markets, also known as cryptomarkets, are websites located on the Darknet and designed to allow the trafficking of illicit products, mainly drugs. This study aims at presenting the added value of combining digital, chemical and physical information to reconstruct sellers' activities. In particular, this research focuses on Evolution, one of the most popular cryptomarkets active from January 2014 to March 2015. Evolution source code files were analysed using Python scripts based on regular expressions to extract information about listings (i.e., sales proposals) and sellers. The results revealed more than 48,000 listings and around 2700 vendors claiming to send illicit drug products from 70 countries. The most frequent categories of illicit drugs offered by vendors were cannabis-related products (around 25%) followed by ecstasy (MDA, MDMA) and stimulants (cocaine, speed). The cryptomarket was then especially studied from a Swiss point of view. Illicit drugs were purchased from three sellers located in Switzerland. The purchases were carried out to confront digital information (e.g., the type of drug, the purity, the shipping country and the concealment methods mentioned on listings) with the physical analysis of the shipment packaging and the chemical analysis of the received product (purity, cutting agents, chemical profile based on minor and major alkaloids, chemical class). The results show that digital information, such as concealment methods and shipping country, seems accurate. But the illicit drugs purity is found to be different from the information indicated on their respective listings. Moreover, chemical profiling highlighted links between cocaine sold online and specimens seized in Western Switzerland. This study highlights that (1) the forensic analysis of the received products allows the evaluation of the accuracy of digital data collected on the website, and (2) the information from digital and physical/chemical traces are complementary to evaluate the practices of the online selling of illicit drugs on cryptomarkets

A geographical analysis of trafficking on a popular darknet market

© 2017 Elsevier B.V. Cryptomarkets are online marketplaces, located on the darknet, that facilitate the trading of a variety of illegal goods, mostly drugs. While the literature essentially focus on drugs, various other goods and products related to financial or identity fraud, firearms, counterfeit goods, as well as doping products are also offered on these marketplaces. Through the analysis of relevant data collected on a popular marketplace in 2014–2015, Evolution, this research provides an analysis of the structure of trafficking (types and proportions of products, number of vendors and shipping countries). It also aims at highlighting geographical patterns in the trafficking of these products (e.g. trafficking flows, specialisation of vendors and assessment of their role in the distribution chain). The analysis of the flow of goods between countries emphasises the role of specific countries in the international and domestic trafficking, potentially informing law enforcement agencies to target domestic mails or international posts from specific countries. The research also highlights the large proportion of licit and illicit drug listings and vendors on Evolution, followed by various fraud issues (in particular, financial fraud), the sharing of knowledge (tutorials) and finally goods, currencies and precious metals (principally luxury goods). Looking at the shipping country, there seems to be a clear division between digital and physical products, with more specific information for physical goods. This reveals that the spatial analysis of trafficking is particularly meaningful in the case of physical products (such as illicit drugs) and to a lesser extent for digital products. Finally, the geographical analysis reveals that spatial patterns on Evolution tend to reflect the structure of the traditional illicit market. However, regarding illicit drugs, country-specificity has been observed and are presented in this article

Cleaning deteriorated elements of ammunition: Development of a procedure applied to cartridge cases from the Second World War.

Deteriorated elements of ammunition can be found while investigating different types of events. Exposure to adverse environmental conditions may lead to metal alteration (corrosion) or organic material deposition (contaminations) on the exposed elements of ammunition. From a forensic perspective, both types of deterioration pose challenges when observing marks left by the firearms used to discharge the corresponding ammunition (e.g. firing pin, extractor). The longer the time of exposure to the adverse environmental conditions, the more challenging the observation of such marks. A literature review highlighted three previously published restorative methods used to clean deteriorated elements of ammunition. The aim of this research is to develop a cleaning procedure applicable to cartridge cases exposed to adverse environmental conditions, while avoiding the degradation of marks left by the firearms used to discharge the corresponding ammunition. A first batch of 21 brass cartridge cases dating back to the Second World War (WWII) was used to develop a cleaning sequence involving the three methods. The efficiency of each restorative method was qualitatively assessed using optical macroscopy and the Evofinder® ballistic identification system. The developed sequence relies on successive applications of Tickopur® TR 7 (a diluted soft metal cleaner), sulfuric acid and finally Aqua Regia (HCl 37% and HNO <sub>3</sub> 75%), all of them involving ultrasonic baths. The resulting cleaning sequence was subsequently applied to three batches of Second World War cartridge cases discovered in France and Russia. This sequential procedure allows the effective cleaning of WWII brass cartridge cases while highlighting different marks left by firing pins, extractors, ejectors, and breech faces. Applying a forensic analysis and comparison process to the marks highlighted on these elements of ammunition can support the verification of historical facts when reconstructing events which took place more than seventy years ago

Secondary transfer of organic gunshot residues: Empirical data to assist the evaluation of three scenarios.

The present study aimed at providing data to assess the secondary transfer of organic gunshot residues (OGSR). Three scenarios were evaluated in controlled conditions, namely displacing a firearm from point A to point B, a simple handshake and an arrest involving handcuffing on the ground. Specimens were collected from the firearm, the hands of the shooter and the non-shooter undergoing the secondary transfer in order to compare the amounts detected. Secondary transfer was observed for the three scenarios, but to a different extent. It was found that displacing a firearm resulted in secondary transfer in <50% of the experiments. The firearm also had an influence, as contrary to the pistol, no secondary OGSR were detected using the revolver. Shaking the hand of the shooter also transferred OGSR to the non-shooter's hand. In that case, the amount of OGSR was generally higher on the shooter than on the non-shooter. Finally, the largest secondary transfer was observed after the arrest with handcuffing with positive results in all cases using the pistol. In that scenario, the amounts on the shooter and the non-shooter were in the same range. This study highlights that the secondary transfer must be taken into account in the interpretation of OGSR. Indeed, an individual's hands might be contaminated by handling a firearm or having physical contact with a shooter

Comparison of three bullet recovery systems

Comparing the marks left on questioned bullets to those left on reference bullets is the main aim of a firearm identification expertise. Thus, producing reference bullets with a questioned firearm is an essential step. Different kinds of system have been developed to safely recover bullets fired from questioned firearms. However, the performance of each system and its impact on traces left on the bullets have not been addressed. Three bullet recovery systems – a horizontal water tank, a cotton tube and a recently designed fleece – were used to fire seven types of ammunition of various type, shape and casing. The bullets were then described and images of their surface were acquired with an automatic system to study the impact of each system on the bullets. The water tank is the more efficient system in terms of quality of the marks. However, it cannot be used to fire every type of ammunition. Some of them, such those used by law enforcement, tend to be damaged with this system. A way to mitigate the problem is to use the cotton or the fleece-based systems, the latter being more universal. It requires a cleaning step to remove all the fibres from the surface of the bullet, but the marks left by the weapon are still of interest

Drogues sur Internet : Etat des lieux sur la situation en Suisse

Où trouve-t-on des drogues sur Internet, comment sont-elles vendues, quelle est la taille du marché et quelle est la place de la Suisse dans celui-ci ? Pour essayer de répondre à ces questions, Addiction Suisse et l’Ecole des Sciences Criminelles de l’UNIL ont collecté et analysé un ensemble de données pertinentes sur mandat de l’Office Fédéral de la Santé Publique. Internet est constitué de trois composants de base : un réseau de transmissions (câbles ou ondes), un système de reconnaissances des dispositifs interconnectés (le protocole IP) et des protocoles de transport de données. Ensemble, ils permettent l’usage d’applications (web, e-mail, messaging) de communication et de partage d’information. Il est possible de trouver et d’acheter des drogues sur de nombreuses applications incluant les sites web, qu’ils soient dissimulés ou non, mais aussi les réseaux sociaux et les applications de messagerie. On peut y rencontrer différentes stratégies de promotion, différents espaces de vente mais aussi d’évaluation des stupéfiants proposés. D’autres produits comme des médicaments, des produits dopants et des nouvelles substances psychoactives (NPS) sont aussi mis en vente. Les connaissances concernant la vente de stupéfiants sur les différentes applications présentes sur Internet sont encore balbutiantes, à l’exception des cryptomarchés qui sont souvent spécialisés dans ce domaine. Il s’agit de plateformes de vente qui permettent un certain anonymat. Le recours à des infrastructures spécifiques (appelés darknets), à des espaces du web qui ne sont pas ou peu régulés (les darkwebs), à des communications cryptées et à des cryptomonnaies comme le Bitcoin® permettent cet anonymat. Les darkwebs, et les cryptomarchés qu’ils hébergent, restent cependant minuscules par rapport à l’ensemble des espaces du Web. La vente de stupéfiants sur les cryptomarchés a été révélée par le site Silk Road. Depuis, de nombreux sites similaires sont apparus mais avec des durées de vie souvent assez courtes, en raison de fraudes internes ou de l’intervention des forces de l’ordre. Les sites reposent sur la gestion par des administrateurs et sur des annonces qui décrivent le produit, son prix et les conditions de son acquisition. Ils s’appuient aussi sur l’évaluation des produits et des vendeurs par les acheteurs. Ils sont ainsi, dans leur forme, similaires à de nombreux sites connus comme ebay®. Pour comprendre la place que joue la Suisse dans ce marché, des téléchargements des données de l’un des principaux cryptomarchés de stupéfiants (AlphaBay, actif de fin 2014 à juillet 2017) ont été réalisés. Ils montrent que les pays de provenance les plus cités sont les pays anglo-saxons (États-Unis, Canada, Australie, Royaume-Uni) les Pays-Bas et l’Allemagne. La Suisse occupe une place moins importante mais, si l’on considère sa taille, son rôle n’est pas négligeable au niveau de la vente. Ainsi, 57 comptes vendeurs déclarant se situer en Suisse ont réalisé un peu plus de dix mille transactions pour un chiffre d’affaires d’environ 1,3 million de francs sur AlphaBay. La vente de stimulants concerne 85% de ces transactions avec surtout de petites quantités et des prix proches de ceux du marché physique. Ces ventes ne représentent en fait qu’une très petite partie du marché des stupéfiants en Suisse mais quelques vendeurs réalisent des chiffres d’affaires conséquents allant jusqu’à près de 30'000 dollars par mois. Il existe peu de données sur les personnes en Suisse qui commandent des drogues sur Internet. Une analyse des données du Global Drug Survey, suggère que l’achat sur le web et sur les darkwebs reste limité, mais avec une tendance à l’augmentation. Des données plus anciennes montrent que le cannabis et les stimulants sont les produits les plus commandés par les acheteurs suisses. Ceux-ci commandent chez des vendeurs en Suisse mais aussi à l’étranger, notamment en Allemagne, aux Pays-Bas, au Royaume-Uni et en Belgique. Les commandes à l’étranger sont généralement associées à des quantités plus importantes mais restent relativement modestes. En moyenne, hormis pour le cannabis, les achats dépassent rarement 5 à 10 grammes en moyenne. Un petit sondage auprès des polices cantonales a montré que les enquêtes concernant les achats de stupéfiants sur Internet restent jusqu’ici assez rares. Elles résultent souvent d’une information transmise par un informateur ou de la découverte d’un ordinateur allumé lors d’une perquisition. Le cas le plus fréquent concerne les colis interceptés par les douanes avec de petites quantités commandées sur Internet, le plus souvent du cannabis, des stimulants ou des hallucinogènes. On retiendra de cette exploration des données sur les marchés des drogues sur Internet, que ceux-ci se trouvent dans différents espaces du web, notamment les darkwebs, mais qu’ils ne semblent jusqu’ici constituer qu’une très petite partie du marché des stupéfiants, en tout cas en Suisse. Il y a toutefois quelques indications que le phénomène tend à s’étendre, même si cela se fait d’une manière moins rapide qu’on pouvait le penser. Comme d’autres innovations, la vente et l’achat de substances psychoactives sur Internet suivent probablement une phase d’adoption dans un groupe restreint d’individus avant de, peut-être, devenir un phénomène plus large

Characterising the online weapons trafficking on cryptomarkets

Weapons related webpages from nine cryptomarkets were manually duplicated in February 2016. Information about the listings (i.e. sales proposals) and vendors' profiles were extracted to draw an overview of the actual online trafficking of weapons. Relationships between vendors were also inferred through the analysis of online digital traces and content similarities. Weapons trafficking is mainly concentrated on two major cryptomarkets. Besides, it accounts for a very small proportion of the illicit trafficking on cryptomarkets compared to the illicit drugs trafficking. Among all weapon related listings (n=386), firearms only account for approximately 25% of sales proposal since the proportion of non-lethal and melee weapons is important (around 46%). Based on the recorded pseudonyms, a total of 96 vendor profiles were highlighted. Some pseudonyms were encountered on several cryptomarkets, suggesting that some vendors may manage accounts on different markets. This hypothesis was strengthened by comparing pseudonyms to online traces such as PGP keys, images and profiles descriptions. Such a method allowed to estimate more accurately the number of vendors offering weapons across cryptomarkets. Finally, according to the gathered data, the extent of the weapons trafficking on the cryptomarkets appear to be limited compared to other illicit goods

How to recognize the traces left on a crime scene by a 3D-printed Liberator?: Part 1. Discharge, exterior ballistic and wounding potential

The Liberator is a firearm that can be manufactured from its blueprints, using a 3D-printer. This weapon made of nineteen pieces – eighteen in printed plastic and one metallic nail – raises questions such as its ability to fire a round, its wounding potential and the traces produced by its discharge. In particular, knowledge must be gained to infer that a 3D-printed handgun was used, reconstruct the shooting event involving such handgun, and gather information related to the type of 3D-printed handgun used. This study focused on the traces that could orientate forensic investigations when the use of a 3D-printed Liberator is suspected. In a first step, the Liberator was investigated to study its behaviour during the discharge and characterize traces produced by the discharge. To fulfil this goal, some Liberators were printed and assembled. Six Liberators fired a round. The discharge of the weapons was done under specific conditions allowing to collect ballistics data and traces produced by the shooting. The results showed that the barrel tended to break between the ignition of the primer and the moment the projectile exited the muzzle. The speed of the projectiles reached 140 m/s when the barrel broke, while it was about 170 m/s when barrel remained intact. The trajectory of the projectiles was sometimes disrupted, and the projectile tumbled on itself. It was thus very difficult to characterize the trajectory. The cavity wound caused by the fastest bullet was typical of a handgun wound firing a FMJ projectile (penetration of 21 cm in ballistics soap). On the other hand, the cavity caused by the slowest bullet was more representative of a splinter wound (penetration of 14 cm in ballistics soap). The study of gunshot residues collected on adhesive targets showed the presence of unburnt particles and small perforations caused by polymer pieces that concentrated around the entry holes