Deep learning in forensic shotgun pattern interpretation-A proof-of-concept study

Little is known about the potential of artificial intelligence in forensic shotgun pattern interpretation. As shooting distance is among the main factors behind shotgun patterning, this proof-of-concept study aimed to explore the potential of neural net architectures to correctly classify shotgun pattern images in terms of shooting distance. The study material comprised a total of 106 shotgun pattern images from two discrete shooting distances (n = 54 images from 10 m and n = 52 images from 17.5 m) recorded on blank white paper. The dataset was used to train, validate and test deep learning algorithms to correctly classify images in terms of shooting distance. The open source AIDeveloper software was used for the deep learning procedure. In this dataset, a TinyResNet-based algorithm reached the highest testing accuracy of 94%. Of the testing set, the algorithm classified all 10 m patterns correctly, and misclassified one 17.5 m pattern. On the basis of these preliminary data, it seems achievable to develop algorithms that would serve as a beneficial tool for forensic investigators when estimating shooting distances from shotgun patterns. In the future, studies with larger and more complex datasets are needed to develop robust and applicable algorithms for forensic shotgun pattern interpretation.Peer reviewe

Post-mortem computed tomography in forensic shooting distance estimation: a porcine cadaver study

Objectives Gunshot wounds are frequently studied using computed tomography (CT) to examine tissue damage. In this study, we aimed to test the potential of post-mortem CT (PMCT) in shooting distance estimation at distances 0–100 cm. We hypothesized that in addition to the wound channel, we could also potentially detect tissue damage caused by muzzle pressure on PMCT. Results A total of 59 gunshot wounds (23 contact shots, 21 close-range shots, 15 distant shots) were inflicted on eight piglet carcasses with a .22 Long Rifle handgun. PMCT scans were obtained using clinical equipment, and they were evaluated for wound characteristics by visual inspection and numeric measurements. In our data, contact shots could be clearly distinguished from close-range and distant shots by a hyperdense ring-shaped area surrounding the outermost part of the wound channel. Close-range and distant shot wounds did not have this feature and were difficult to distinguish from each other. The mean wound channel diameter ranged from 3.4 to 5.4 mm, being smallest in contact shots and largest in distant shots. These preliminary findings suggest that PMCT may aid the estimation of shooting distance. As this study only addressed low velocity gunshot wounds in carcasses, further studies are warranted.Peer reviewe

Post-mortem computed tomography in forensic shooting distance estimation: a porcine cadaver study

Objectives Gunshot wounds are frequently studied using computed tomography (CT) to examine tissue damage. In this study, we aimed to test the potential of post-mortem CT (PMCT) in shooting distance estimation at distances 0–100 cm. We hypothesized that in addition to the wound channel, we could also potentially detect tissue damage caused by muzzle pressure on PMCT. Results A total of 59 gunshot wounds (23 contact shots, 21 close-range shots, 15 distant shots) were inflicted on eight piglet carcasses with a .22 Long Rifle handgun. PMCT scans were obtained using clinical equipment, and they were evaluated for wound characteristics by visual inspection and numeric measurements. In our data, contact shots could be clearly distinguished from close-range and distant shots by a hyperdense ring-shaped area surrounding the outermost part of the wound channel. Close-range and distant shot wounds did not have this feature and were difficult to distinguish from each other. The mean wound channel diameter ranged from 3.4 to 5.4 mm, being smallest in contact shots and largest in distant shots. These preliminary findings suggest that PMCT may aid the estimation of shooting distance. As this study only addressed low velocity gunshot wounds in carcasses, further studies are warranted.Peer reviewe

Unnatural-cause mortality patterns of Northern Finnish men and women diverge in adolescence – A 52-year follow-up

The Finnish population has a long life expectancy but ranks high in unnatural deaths on the European scale. Mortality has historical regional discrepancy in Finland, as Northern Finns are overrepresented in both natural and unnatural deaths. This study aimed to characterize the age- and sex-related trends in unnatural mortality among Northern Finns. Altogether 12 143 individuals, constituting >95% of births in Northern Finland in 1966, were followed up for a median of 52 years. The mortality patterns of this population were studied using death record data. Crude annual mortality rates were calculated and graphed for 10-year age strata (all-cause, natural-cause, and unnatural-cause mortality, as well as accident, suicide, and homicide mortality). Cox regression was used to analyze the sex discrepancy in mortality. A total of 874 deaths (7.2%) occurred during the follow-up period. Women had 47% and 73% lower risks of any death and unnatural death than men, respectively. From the second decade of life onwards, the unnatural mortality of men was 3–5 times that of women. Accident and suicide mortality rates of men were 2–13 and 2–3 times those of women, respectively. Homicides were rare among either sex. We conclude that Northern Finnish women have a substantially lower risk of all-cause mortality and unnatural mortality than men. To aid the development of preventive strategies, future studies should aim to identify the underlying factors behind unnatural mortality. Primarily, emphasis should be placed on the increased mortality of men from the second decade of life onwards.Peer reviewe

Gravidity, parity and knee breadth at midlife: a population-based cohort study

Gestation increases the biomechanical loading of lower extremities. Gestational loading may influence anthropometrics of articular surfaces in similar means as bone diaphyseal properties. This study aimed to investigate whether gravidity (i.e. number of pregnancies) and parity (i.e. number of deliveries) is associated with knee breadth among middle-aged women. The study sample comprised 815 women from the Northern Finland Birth Cohort 1966. The median parity count of our sample was 2 and the median gravidity count 3. At the age of 46, questionnaires were used to enquire gravidity and parity, and posteroanterior knee radiographs were used to obtain two knee breadth parameters (tibial plateau mediolateral breadth (TPML) and femoral condylar mediolateral breadth (FCML)) as representatives of articular size. The associations of gravidity and parity with knee breadth were analyzed using general linear models with adjustments for height, weight, leisure-time physical activity, smoking, and education years. Individuals with osteoarthritic changes were excluded from our sample. The mean TPML in our sample was 70.3 mm and the mean FCML 71.6 mm respectively. In the fully adjusted models, gravidity and parity showed positive associations with knee breadth. Each pregnancy was associated with 0.11–0.14% larger knee breath (p < 0.05), and each delivery accounted for an increase of 0.20% in knee breadth (p < 0.01). Between-group comparisons showed that multiparous women had 0.68–1.01% larger knee breath than nulli- and primiparous women (p < 0.05). Pregnancies and deliveries seem to increase the mediolateral breadth of the knee. This increase is potentially associated with increased biomechanical loadings during gestation.Peer reviewe

Fame after Death: The Unusual Story of a Finnish Mummy and Difficulties Involving its Study

The cool, ventilated milieus beneath the floors of old Finnish churches are responsible for the natural mummification in church graves. One good example of such preservation are the remains of an early 17th-century vicar of Kemi parish, Nikolaus Rungius. He died in 1629 and was put to rest under the old Keminmaa Church in Finnish Lapland. The parish began exhibiting his preserved body in the 18th century after which Vicar Rungius – a locally revered man of cloth in life – gained wide posthumous fame. His dead body became a powerful means to encourage and strengthen people’s faith. The mummy has maintained a human form but has lost its right forearm. On top of that the computed tomography scanning conducted in 2011 revealed that the head was not normally attached. It is unclear when it happened or how but a suspicion arose that once the neck was damaged the head could have fallen to the ground and shattered. A serious concern was whether the head of the mummy was really that of Vicar Rungius as a headless vicar would undoubtedly have prompted a substitution with another mummified head in order to maintain a powerful incentive to the parishioners’ faith.Kuolemanjälkeisestä maineesta: epätavallinen tarina suomalaisesta muumiosta ja sen tutkimiseen liittyvistä ongelmista Viileä, hyvin tuulettuva ympäristö vanhojen suomalaisten kirkkojen lattioiden alla luo olosuhteet luonnolliselle muumioitumiselle kirkkohaudoissa. Hyvänä esimerkkinä tällaisesta säilymisestä voidaan pitää 1600-luvun alkupuolella eläneen Kemin seurakunnan kirkkoherran Nikolaus Rungiuksen muumiota. Kirkkoherra kuoli vuonna 1629 ja hänet haudattiin Suomen Lapissa sijaitsevan Keminmaan vanhan kivikirkon alle. Hänen muumioitunut ruumiinsa on seurakunnan toimesta ollut näytteillä 1700-luvulta lähtien, minkä jälkeen kirkkoherra Rungius – jo eläessään paikallisten kunnioittama kirkonmies – saavutti laajalle levinneen kuolemanjälkeisen maineen. Hänen ruumistaan tuli merkittävä keino rohkaista ja lujittaa ihmisten uskoa. Muumio on säilyttänyt ihmismuotonsa, mutta menettänyt oikeanpuoleisen kyynärvartensa. Sen lisäksi vuonna 2011 suoritettu tietokonetomografia paljasti, ettei muumion pää ollut normaalisti kiinni torsossa. On epäselvää, milloin ja miten pää on irronnut, mutta sen irtoaminen herätti epäilyksen, että niskan vahingoituttua pää oli saattanut pudota maahan ja rikkoontua. Olikin pohdittava, onko muumion pää todellakin kirkkoherra Rungiuksen, sillä kirkkoherran päättömyys olisi epäilemättä nopeasti johtanut pään korvaamiseen jollain toisella muumioituneella päällä seurakuntalaisten uskon vaikutusvaltaisen kannustimen säilyttämiseksi