Emergency services were notified that a 72-year-old male was injured by an “exploded” pepper grinder. Resuscitation performed by the emergency personnel that arrived shortly thereafter was unsuccessful. The crime scene investigation found the victim lying on a concrete floor of a covered terrace attached to a house. The victim’s chest was covered with blood, and a horizontal entrance wound was observed in the region of his heart. Two homemade pepper grinders were found on a table (Fig. 1a). Two holes were observed on the metal container of one of the pepper grinders: an 8-cm-long hole facing the garden and an 8.7-cm-long hole facing the building and the chairs (Figs. 1b and 2c). One piece of the broken blade was found in the grinder (Fig. 2d), but no other blade pieces were found. Two chairs were observed between the table and the building – blood stains were found around one, which was farther from the pepper grinder (Fig. 1c). The container of the pepper grinder was made from a tin Christmas cookie box (Fig. 2a, b), and the motor came from a vacuum cleaner.

The crime scene (a-c): the pepper grinder (yellow circle) is situated on the wooden table of the terrace (the victim was sitting on the chair in front of the white plastic bucket when he suffered the injury), the blue circle indicates the damage on the pepper grinder, the yellow arrows indicate the blood stains around the chair where the victim was sitting, the red arrow illustrates the trajectory of the broken blade towards the original position of the victim

The pepper grinder (a, b), the damage on the container (c), the blade fragment found within the container (d)

A witness stated that the deceased individual was his friend of his who came to see him to show off his homemade pepper grinder. The victim set the pepper grinder on the table, plugged it into the electrical socket, and turned it on. After a few seconds, the witness heard a loud “bang” from the pepper grinder and noticed metal splinters flying out from it. The deceased reached for his heart and immediately fell from the chair below the table.

Postmortem computed tomography (PM-CT) of the victim was performed prior to autopsy. PM-CT revealed a 93 × 20-mm-sized metal blade in his chest, situated in the pericardium, pulmonary trunk, ascending aorta and superior left lobe of the lung (Fig. 3a-e). The thoracic cavity contained blood, and the sternum and third rib were fractured. A rectangular fracture line could be observed on the sternum (Fig. 3f).

PM-CT (GE Revolution 256; spectral acquisition for metal artifact reduction; tube voltage GSI mode (80/140 kV) 400 mA; rotation time: 0.8 s, pitch: 0.516; slice thickness 0.625 mm; increment 0.3125 mm). Axial (a), coronal (b) and sagittal (c) planes adjusted to the direction of the blade. The blade was situated in the chest obliquely, heading left and slightly upwards: its longitudinal axis was 37° to the frontal plane and 16° to the horizontal plane (d, e). A 3D reconstruction image of the sternum injury is shown in (f); note the rectangular fracture matching the bent part of the blade. The position of the blade observed on PM-CT is consistent with the trajectory determined from the crime scene examination if the victim was turned towards the pepper grinder (with his chest facing it)

The external investigation revealed a 74-mm-long, almost horizontal entrance wound with sharp edges and rounded angles on the victim’s chest (Fig. 4a). Other injuries included abrasions of the skin above the thoracic vertebrae and minor abrasions on the victim’s forehead. The entrance wound of the chest was surrounded by a 3–10-mm-sized collar-like hemorrhage in the subcutaneous fat tissue. The chest muscles were penetrated, and a 4.5-cm-long horizontal injury was observed involving the sternum and the third rib (Fig. 4b). The left side of the victim’s chest contained 600 ml of blood. The metallic blade fragment detected previously in the PM-CT imaging was observed in the upper part of the pericardium, the pulmonary trunk, the initial part of the left pulmonary artery and in the ascending aorta (Fig. 4c, d). The fragment also penetrated the upper lobe of the lung behind the pulmonary arteries, where it was surrounded by bleeding that extended for 1 cm in all directions. The pericardium contained 50 ml of blood. Apart from these injuries, there was a 2 × 3-cm-sized region of subcutaneous bleeding at the victim’s forehead; a hypovolemic spleen, shock kidneys, mild heart hypertrophy (390 g) and moderate generalized atherosclerosis were also found. The removed blade is shown in Fig. 5.

Autopsy findings. Entrance wound situated between 1.0 and 8.4 cm from the midline, with a distance of 136–138 cm to the victim’s feet (a), injury of the chest wall (b), blade position (in situ after partial autopsy, without repositioning) (c, d)

The blade removed during autopsy (length: 93 mm, width: 20 mm, thickness: 0.7 mm, weight: 8 g). It was created from a double-sided hacksaw blade: a circular hole was drilled in the middle for the axis, and the last 5 mm of the two ends was bent at 45° (Fig. 5)

Histological analysis of the aortic sample and lung sample revealed extensive bleeding without any signs of inflammation. Toxicological analysis (Shimadzu HPLC module with UV spectral library and Waters Acquity UPC2 supercritical fluid chromatograph with Waters Xevo TQ-S triple quadrupole mass detector) detected theophylline (274 ng/ml) and caffeine (3010 ng/ml). No ethanol was detected in the blood and urine samples (Agilent Technologies 7890 A headspace gas chromatography with flame ionization detector).

The cause of death was determined to be hemorrhagic shock due to the penetrating injury of the pulmonary arteries and the aorta by a fragment from the blade of the pepper grinder. The substances found during toxicological analysis were not considered to be contributory to the victim’s death.