The marks left by the bite of a subject (bitemark) represent an unequivocal character, being useful in identifying the possible perpetrator of a crime. To date, the analysis of bitemarks is mainly based on the direct vision of photographic finds and on the visual comparison with the teeth of the hypothetically responsible person. However, the bitemark also retains three-dimensional characteristics detectable with a 3D scanner. In this pilot study, an innovative method of bitemark analysis, utilizing a three-dimensional scanner and some software, will be introduced, enabling a quantitative comparison of bitemarks and their corresponding human dentitions. For this purpose, 10 complete plaster models (human dentitions) of 10 adult subjects were used to make 20 experimental bitemarks on dentistry wax. All materials were individually scanned with the iTero® 3D scanner and reworked with MeshMixer software. A visual analysis of the characteristics and a computerized analysis with the CloudCompare software were also performed. Study showed a different trend of the distribution curves of the points which were obtained comparing the human dentition and coincident and non-coincident bitemarks. Current results support that the intraoral 3D scanner allows the fast record and the preservation of the three-dimensional characteristics of the bitemarks, and it allows computerized analyses to be carried out.

Hair is a feature that is only found in mammals. In all species, it is an epidermal protrusion composed of an outer cuticle, middle cortex, and inner medulla. Hair\'s primary purpose in mammals is to aid with thermoregulation. Every domestic animal species has a distinct hair pattern that can be used in forensic investigations. The aim of the present study is to observe the different animal hairs under stereomicroscope for forensic analysis. Hair is a unique characteristic seen only in mammals. It is an epidermal protrusion composed of an outer cuticle, middle cortex, and inner medulla in all species. The primary function of hair in animals is to aid with thermoregulation. Every domestic animal species has a specific hair pattern that forensic investigators can employ. The shaft profile was straight in all the animal hairs. In the proximal end, the root was absent because the hair was cut from the respective animals. Cuticles were absent in all the hair strands. The surface texture was smooth in dog hair, rough and spiculated in cat hair, and coarse in horse and rat hair. Microscopic examination of hairs reveals morphological distinctions that allow animal hairs from different species to be distinguished. In forensic investigations, microscopic examinations of various animal hairs are useful.

BACKGROUND: In Tunisia, since the January 2011 revolution, there has been considerable media interest in violence, particularly homicides. A popular perspective is, aside from any politically motivated killings, of a rise in homicides from year to year. In the absence of Tunisian national homicide statistics, a more accurate picture may be obtainable from area pathologist records.
OBJECTIVE: To examine annual homicide rates from post-mortem data for the second largest administrative area of Tunisia, Sfax, with a mixed urban-rural population of about one million people.
METHODS: All victims of common law homicide for the region are taken to the forensic department of one hospital in Sfax. We conducted a retrospective and descriptive study of all such cases of homicide for the 9 year period from the date of the fall of the Tunisian government in 14 January 2011 to 31 December 2019 and linked these data to those from earlier studies in the same department.
RESULTS: One hundred and nine victims of unlawful homicide were identified during this nine year period, with an average of 12 cases per year and a peak of 17 cases in 2016, yielding a broadly consistent rate of 1.2 homicides per 100,000 inhabitants and no consistent pattern in fluctuations. Just over two-thirds of the victims were men. Mean age of victims was 34.85 years (range 8-90 years). Just under half were married (45%); largest employment groups were of low-paid casual workers (40%) or unemployed (28%). One third of the killings had taken place in a private residence, with interpersonal conflict given as the largest explanatory category; over one quarter were intra-familial and 14% between intimate partners. There was some seasonal variation, with nearly two-thirds of homicides occurring in the spring and summer months.
CONCLUSIONS: Contrary to press hype, we found no evidence of rising homicide rates in Southern Tunisia, although this does represent a different picture from that in the north of the country. The seasonal variation would merit further exploration as it raises questions around impact of fluctuations in mental health.

The use of modern technologies that can help optimise the collection of evidence that contains Gunshot Residue (GSR) from crime scene investigation leads to obtaining better results in forensic laboratories. With this objective, equipment based on LIBS (Laser Induced Breakdown Spectroscopy) technology has been developed named iForenLIBS. This study intends to evaluate the effective capacity of the aforementioned system. To do this, results were gathered from the analysis of real samples using LIBS equipment and were compared to those obtained by way of Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDX) in the laboratory. The system has verified its capacity to analyse GSR particles through simultaneous detection of the three characteristic elements of ammunition used (Sb-Pb-Ba) even in stub where only a single particle was found.

The study of gunshot residue (GSR) patterns can assist in the reconstruction of shooting incidences. Currently, there is a real need of methods capable of furnishing simultaneous elemental analysis with higher specificity for the GSR pattern visualization. Laser-Induced Breakdown Spectroscopy (LIBS) provides a multi-elemental analysis of the sample, requiring very small amounts of material and no sample preparation. Due to these advantages, this study aims at exploring the potential of LIBS imaging for the visualization of GSR patterns. After the spectral characterization of individual GSR particles, the distribution of Pb, Sb and Ba over clothing targets, shot from different distances, were measured in laser raster mode. In particular, an array of spots evenly spaced at 800μm, using a stage displacement velocity of 4mm/s and a laser frequency of 5Hz was employed (e.g. an area of 130×165mm2 was measured in less than 3h). A LIBS set-up based on the simultaneous use of two spectrographs with iCCD cameras and a motorized stage was used. This set-up allows obtaining information from two different wavelength regions (258-289 and 446-463nm) from the same laser induced plasma, enabling the simultaneous detection of the three characteristic elements (Pb, Sb, and Ba) of GSR particles from conventional ammunitions. The ability to visualize the 2D distribution GSR pattern by LIBS may have an important application in the forensic field, especially for the ballistics area.

Specific analytical procedures are requested for the forensic analysis of pre- and post-blast consumer firework samples, which present significant challenges. Up to date, vibrational spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) have not been tested for the analysis of post-blast residues in spite of their interesting strengths for the forensic field. Therefore, this work proposes a simple and fast procedure for the sampling and analysis of consumer firework post-blast residues by a portable FTIR instrument with an Attenuated Total Reflection (ATR) accessory. In addition, the post-blast residues spectra of several consumer fireworks were studied in order to achieve the identification of their original chemical compositions. Hence, this work analysed 22 standard reagents usually employed to make consumer fireworks, or because they are related to their combustion products. Then, 5 different consumer fireworks were exploded, and their residues were sampled with dry cotton swabs and directly analysed by ATR-FTIR. In addition, their pre-blast fuses and charges were also analysed in order to stablish a proper comparison. As a result, the identification of the original chemical compositions of the post-blast samples was obtained. Some of the compounds found were potassium chlorate, barium nitrate, potassium nitrate, potassium perchlorate or charcoal. An additional study involving chemometric tools found that the results might greatly depend on the swab head type used for the sampling, and its sampling efficiency. The proposed procedure could be used as a complementary technique for the analysis of consumer fireworks post-blast residues.