The man in the mask

A skeletonized body, wearing a black leather bondage mask, was found in a Revolutionary War smokehouse cave with two bullet holes in the back of the head. The body was skeletonized up to the maxillary area but the head region under the mask was well preserved and permitted a positive visual identification. There was evidence that the body had been eaten by small animals and subsequently burned. Investigations into this brutal murder revealed a tale of a bizarre sadomasochistic ritual that attained national prominence.     

The Critical Angle for Perforation versus Ricochet of a .38 CAL. LRN Bullet on a Windshield

From forensic point of view, it is important to clarify the condition whether ricochet or perforate for a bullet fired toward the automobile windshield. The purpose of this study was to specify the critical angle at which the ricochet of the fired bullet takes place. To estimate the result of firing, a rigid‐body dynamics simulation of the bullet together with the test‐firing using .38 CAL. LRN bullet was examined. It was found both from numerical simulation and firing test that when the incidence angle is <45°, a complete perforation of the windshield was observed, whereas the bullet ricocheted remaining a characteristic damage on the windshield when the incidence angle is >60°. To measure the static failure resistance of various windshields, static indentation test was also examined.     

A Bayesian approach based on Kalman filter frameworks for bullet identification

When a bullet is fired from a barrel, random imperfections in the interior surface of the barrel imprint 3-D micro structures on the bullet surface that are seen as striations. Despite being random and non-stationary in nature, these striations are known to be consistently reproduced in a unique pattern on every bullet. This is a key idea in bullet identification. Common procedures in the field of automatic bullet identification include extraction of a feature profile from bullet image, profile smoothing and comparison of profiles using normalized cross correlation. Since the cross correlation based comparison is susceptible to high-frequency noise and nonlinear baseline drift, profile smoothing is a critical step in bullet identification. In previous work, we considered bullet images as nonlinear non-stationary processes and applied ensemble empirical mode decomposition (EEMD) as a preprocessing algorithm for smoothing and feature extraction. Using EEMD, each bullet average profile was decomposed into several scales known as intrinsic mode functions (IMFs). By choosing an appropriate range of scales, the resultant smoothed profile contained less high-frequency noise and no nonlinear baseline drift. But the procedure of choosing the proper number of IMFs to reduce the high-frequency noise effect was manual. This poses a problem in comparison of bullets whose images contained less or more noise in comparison to others because their useful information may be present in the corresponding discarded IMFs. Moreover, another problem arises when the bullet type changes. In this case manual inspection is needed once more to figure out which range of IMFs contain less high-frequency noise for this particular type of bullet. In this paper, we propose a novel combination of EEMD and Bayesian Kalman filter to solve these problems. First the bullet images are rotated using Radon transform. The rotated images are averaged column-wise to acquire averaged 1-D profiles. The nonlinear baseline drifts of averaged profiles are removed using EEMD algorithm. The profiles are then processed by a Kalman filter that is designed to automatically and optimally reduce the effect of high-frequency noise. Using Expectation Maximization (EM) technique, for each averaged profile, the parameters of Kalman filter are reconfigured to optimally suppress the high-frequency noise in each averaged profile. This work is the first effort that practically implements the Kalman filter for optimal denoising of firearm image profiles. In addition, we believe that Euclidean distance metric can help the normalized cross-correlation based comparison. Therefore, in this paper, we propose a comparison metric that is invariant to start and endpoints of firearm image profiles. This metric combines the prized properties of both Euclidean and normalized cross-correlation metrics in order to improve identification results. The proposed algorithm was evaluated on a database containing 180 2-D gray-scale images acquired from bullets fired from different AK-47 assault rifles. Although the proposed method needs more calculations in comparison to conventional methods, the experiments showed that it attained better results compared with the conventional methods and the previous method based on EMD in the field of automatic bullet identification.     

Suicide bomber using a pipe bomb

Suicidal deaths caused by pipe bombs are rare. An 18-year-old man was found dead in a forest by hikers. In immediate proximity to the body, a crater was located obviously induced by a detonation. The postmortem examination revealed severe damage of the head, upper-body and both arms and hands along with the extensive presence of soot and dirt. Particularly noticeable were numerous "entry wounds" and the presence of five bullet like pieces of metal in the body. The young man had a history of drug abuse and psychiatric problems. On the basis of autopsy findings, the conclusions of the police investigation and psychopathological considerations regarding the victim's case-history, discussion centers upon the differentiation between suicide by self-explosion, homicide by explosion or death as a consequence of numerous bullet wounds followed by an attempt to burn the body. Also considered is the possibility of paranoid psychosis induced by cannabis use as a cause of suicide.     

Suicidal gunshot to the nape from a small-bore rifle

A 55-year-old man was found dead on the bed lying on his side in a pool of blood with a bullet entrance hole in the nape. Behind his body, a semi-automatic rifle Remington Nylon, cal. .22 LR, was detected. As the gunshot entrance site was rather unusual for suicide, a forensic autopsy was performed, which showed a contact shot to the nape with the bullet path running upward to the left frontal area. The man had been treated with citalopram for delusional depression, so that a suicidal act seemed plausible, and the autopsy and criminalistic findings were also compatible with this assumption. A remarkable fact of the present case is that a long firearm had been used. Reports on suicidal shots to the nape are comparatively rare in the medicolegal literature and usually refer to pistols or revolvers.     

Firearm suicide committed using an unusual combination of tandem missiles: a bullet, a nail, and a screw

An interesting case of firearm suicide carried out using an unusual type of handmade weapon and a peculiar combination of tandem missiles is presented. A nail and a screw were placed in the rifle barrel ahead of a bullet, and all 3 were simultaneously discharged. The inflicted injury began with 1 common channel, which later split in 2 separate channels, both directed backwards and upwards; one was caused by the screw, ending in the epistropheal body, and the other, caused by the bullet and the nail, penetrated into the cranial cavity, where it bifurcated in 2 branches, one from the bullet, ending in the cerebellar tissue, and the other from the nail, penetrated through the brain stem. The established site of the entrance suicidal wound, the appearance of the weapon, and the unusual missiles are discussed with regard to the available references dealing with different types of nail injuries to the head.     

Confusing injury findings in a suicidal gunshot fired to the chest from a carbine with a sawed-off barrel

The stellate bullet entrance wound is one of the facultative features of a contact shot. For the formation of a star-shaped wound two factors are of special importance: first, an extensive bony support underlying the skin in the entrance region, and second, a strong propellant charge of the cartridge fired. Contact shots to the precordial region usually do not cause stellate entrance wounds, even if high-powered rifle ammunition is used. In the reported case, an injury pattern was observed that was not in line with normal findings and seemed confusing at first. Following a suicidal gunshot to the chest from a sawed-off carbine 98a (cal. 8 x 57 Js), a 4.5 cm wide, gaping bullet entrance wound with radiating tears was found. Instead of the usual pocket, the anterior thoracic wall showed a fist-sized area of destruction with extensive undermining of the subcutis. Not far from the entrance hole, a rib fragment had become displaced retrogradely thus perforating the skin from the inside out. The unusual pattern of findings could be explained by the fact that the barrel had been sawed off: as a result of this manipulation, a considerable part of the propellant charge had been converted outside the barrel, i.e. in the initial section of the bullet path.     

Path of bullet and injuries determined by radiography

Radiography is commonly used to find bullet pathways in forensic pathology. In the case presented here, a man had sustained multiple gunshot wounds and one bullet could not be traced. A radiograph was used to find the bullet and showed an interesting bullet pathway. By observing the bullet pathway on a radiograph, sometimes we can surmise the victim's body posture at the time of an incident.     

DNA identification of skeletal remains by investigator’s intuition

In June 2006 a decapitated woman was found in a parking area of the motorway in the area of Prato (Florence). Since the body was beheaded and no victim’s documents or objects were present at the crime scene, identification at that time was impossible. However, DNA profile from woman’s bones were collected. In the same year (2003), a mother had reported her daughter's disappearance but the two events were not related at that time. About ten years later the mother’s DNA profile was finally acquired for a genetic identification of another girl’s body found in the Ferrara area. These genetic profiles were completely discordant. All these genetic comparisons were carried out on behalf of the prosecutors of the cities involved in the findings of the bodies and in the disappearance complaints, but due to the lack of a database the events remained disconnected. In January 2017, the head of the scientific police of Prato who had followed the investigation and questioned the mother of the missing girl found about ten years later, suggested to the magistrate to order the comparison of the mother's DNA with the genetic profile of the bones found in 2006. This comparison finally allowed the identification of the missing daughter.This story highlights the importance of having forensic DNA database to search for missing persons and how the investigator's intuition can play a key role in resolving criminal cases. In fact, databases of unknown bodies and relatives of missing persons were created in Italy as a part of national DNA database just at the beginning of 2018.     

Dumping of victims in walls

A case is described in which a 58-year-old woman was shot and then dumped in a wall. She was immured under the staircase in the basement of a residential house by the offender, who was acting alone. The body was not found until 8 months later. The victim had been reported missing by members of her family. The cool environment delayed the onset of putrefactive changes so that it was not difficult to conduct forensic pathologic investigations into the bullet wound, with traces of gunpowder residue found on the victim's head. The way in which the offense was committed did not provide any indication of diminished responsibility on the part of the 27-year-old offender, which was reflected in the judicial consequences.     

A possible source of reference DNA from archived treated adhesive lifters

During the course of a double murder trial, it became apparent that the two adhesive lifters from the two cadavers had been mislabeled before being presented in court. The question was raised whether DNA testing from the biological material remaining attached to the lifters could resolve this mix-up. In fatal shooting cases where a bullet has been fired through a body surface, an adhesive lifter is applied directly to the entrance wound. The total nitrite residues, as well as biological material surrounding the wound (blood, hair, tissue) are transferred to the adhesive lifter. The nitrite residues are used for estimating firing distance. In a worst-case scenario, the biological material on the lifter may be the only remaining reference material from a victim. In this paper, we examined whether the biological material retrieved from adhesive lifters could be used for DNA typing after the lifters had been treated for GSR pattern. In as much as the biological material found on the lifters can be typed and profiled following physical and chemical treatment, we submit that archived adhesive lifters can be used as a future source of reference DNA from cadavers where no other sample is available.     

Morphology of bullet wounds when using police ammunition, type QD-P.E.P

6 years after introduction of the police ammunition QD-P.E.P. (9 mm caliber), 9 bullet wounds are presented from forensic investigations along with the results of experimental shots at pig carcasses. The evaluation reveals the characteristic pattern of such bullet wounds: a skin defect which is almost as large as the caliber and has a sharp-edged border thus looking like it has been punched out; the contusion ring ("abrasion ring") is conspicuously narrow. These findings can be explained by the shape and design of the projectile. In regular police work immediate incapacitation has not always been achieved, depending on the entry location of the bullet. Experimental shots at pig carcasses showed that in the case of shots at extremities, the residual energy of the exiting bullet may be sufficient to generate another penetrating bullet wound.     

Gunshot suicide with nasal entry

A man with a long history of depression had recently borrowed a rifle. His body was found on its back in bed in his caravan. A rifle lay over the body with the muzzle pointing towards the head. A suicide note was found at the scene. Autopsy revealed entry via the nose with the track passing through the base of the skull to the right parietal region where the main bullet fragments were located beneath the scalp. The history, scene and autopsy findings were consistent with the gunshot wound being suicidal. We can find only one mention of a suicidal gunshot wound with nasal entry in the English-language literature, although a personal communication informed us of a similar case in the Republic of Ireland within the past two years. We report this case because of its unusual nature.     

Parentage testing on blood crusts from firearms projectiles by DNA typing settles and insurance fraud case

We describe a case of a fraudulent insurance claim. The family of an adult white male (DLF) notified the police of their son's disappearance. After a few weeks, a corpse that presented characteristics similar to those of the DLF was found in advanced stages of decay and was identified by the family as being DLF. The family then filed a claim for the life insurance that DLF had taken out just before he disappeared. Suspicions were raised about the identification of the corpse, because it had been done only visually, and because the insurance policy had been taken out just prior to DLF's disappearance. The insurance company requested a postmortem examination for identification. As the corpse had been cremated immediately after identification by the family, the biological material that was encrusted on the two projectiles removed from the body was used for analysis. The blood crusts provided enough genomic DNA for us to carry out PCR base typing of HLA-DQA1, D1S80, HUMCSF1PO, HUMTPOX, HUMTH01, D3S1744, D12S1090, D18S849, and amelogenin. Results from all loci typing from the corpse presumed to be that of DLF were then compared with that of his alleged biological parents, revealing genetic incompatibility.     

Immunocytochemical examinations of biological traces on expanding bullets (QD-PEP)

When a crime victim has been injured with several different objects, it is of central importance for the forensic investigation to be able to show which object caused which injury, especially if one of the injuries was lethal. In cases of bullet penetration wounds it is often not possible to find such evidence. However, immunocytochemical investigations can accurately match a victim's injury to a particular bullet path through the body. In cases where expanding bullets have been used and the heart or liver has been struck by a projectile, it can be shown that the cells remaining on the bullet stem from those particular organs. In this case the specific cytological evidence was established by means of marking heart- and liver-specific tissue proteins with appropriate antibodies (cardiac troponin I and HepPar 1) followed by disclosure with an appropriate chromogen. Thus, in principle, cells can be used as evidence after being extracted from the projectiles by either damp cotton-wool swabs or adhesive trace evidence tape. Because of the specificity of the used immunocytochemical antibodies, finding evidence of an antigen on a particular projectile proves that it was the object that injured the organs.     

Victim of a dictatorial regime: identification of Mr. Roberto Gomensoro Josman

Forensic cases are ideal to test osteological techniques developed by physical anthropologists. Forensic anthropology is a scientific discipline that applies population-based standards to individual skeletal remains. Many complex techniques are used in an attempt to make a positive identification. Several of these techniques, specifically digital video superimposition and DNA, were used to identify the victim in this case. The purpose of this paper is to describe anthropological techniques used to identify the remains of an unknown person who was later identified as Mr. Roberto Gomensoro Josman, the victim of a Uruguayan dictatorial regime. Mr. Gomensoro Josman disappeared after authorities of the Uruguayan dictatorial government (1973-1984) arrested him. Six days later an unknown body was found floating in Lake Rincon del Bonete. The corpse was found tied with wire and weighted with three large stones used to keep the body submerged. An autopsy was performed and the body was buried as an unknown person in the grave identified as number 10936 of Tacuarembo Cemetery. On December 2002 the Peace and Justice Service asked the local judge to authorize the exhumation of the remains. The exhumed body was headless. An investigation revealed that the local medical examiner who had autopsied the remains on March 1973 had retained the victim's skull in his office. Osteological analysis indicated the victim was a white male in his 20s. Four good quality photographs of Mr. Gomensoro who was known to be missing were compared with the skull. To confirm the identification from the video a DNA analysis was carried out comparing the victim with relatives. DNA typing confirmed the results of the earlier identification.     

A Multimodal Fusion Approach for Bullet Identification Systems

In the field of forensic science, bullet identification is based on the fact that firing the cartridge from a barrel leaves exclusive microscopic striation on the fired bullets as the fingerprint of the firearm. The bullet identification methods are categorized in 2‐D and 3‐D based on their image acquisition techniques. In this study, we focus on 2‐D optical images using a multimodal technique and propose several distinct methods as its modalities. The proposed method uses a multimodal rule‐based linear weighted fusion approach which combines the semantic level decisions from different modalities with a linear technique that its optimized modalities weights have been identified by the genetic algorithm. The proposed approach was applied on a dataset, which includes 180 2‐D bullet images fired from 90 different AK‐47 barrels. The experimentations showed that our approach attained better results compared to common methods in the field of bullet identification.