Medico-legal features of rifled weapons discharge fatalities in Rome (Italy) and analysis of the differences in internal bullet wound paths between suicide and homicide

Abstract

Firearm wounds reppresent a significant cause of mortality worldwide. The differentiation between suicide, homicide, and accidental incidents can be complex, particularly in the absence of clear injuries linked to third-party involvement. Autopsy characteristics of wounds are pivotal in determining the manner of death. A review of the Institute of Legal Medicine of the University of Rome Tor Vergata's database identified 64 deaths due to rifled weapon discharge wounds, excluding accidental deaths. We recorded demographic, circumstantial, and autopsy data for homicides and suicides, with a focus on bullet intrasomatic wound paths analysis. Differences in frequencies of circumstantial data were observed, notably in the locations where victims’ bodies were discovered. Autopsy findings revealed distinct anatomical wound distribution. Bullet wound paths across three anatomical planes indicated patterns associated with the manner of death. Leftward, upward, and backward pathways were unique to suicides, while frontward and rightward pathways strongly indicated homicide. Therefore, comprehensive data integration is essential for accurate forensic diagnosis, and projectile directionality alone should not be considered a definitive criterion to distinguish between suicide and homicide, as similar wound paths may arise in both contexts depending on the circumstances.

Keywords

Rifled weapons homicide suicide autopsy bullet trajectory bullet wound path

Introduction

Firearm discharges are a frequent cause of death globally. The US Centers for Disease Control and Prevention (CDC) reported more than 652,000 deaths from firearms wounds in the United States between 1999 and 2018.^1,2 In Europe, an estimated 7000 people per year die from firearm wounds in suicides, homicides, and accidental cases.^3,4

According to the 2004–2005 International Crime Victims Survey (ICVS), about 13% of Italian families possess a firearm. In Rome, around 10% of the population owns a firearm, with 5.7% having guns.⁵

Distinguishing between suicide, homicide, and accidental events can be challenging, particularly in the absence of injuries clearly attributable to third-party action. Investigating fatal firearms injuries necessitates meticulous autoptic examination, comprehensive collection of circumstantial information, detailed personal and family history of the victim, and additional technical findings to determine the cause and manner of death.⁶

Common indicators of suicide typically include the firearm is located near the body,⁷ a single discharge fired in contact with the skin with an internal path aligning with self-infliction, and ballistic investigation generally confirming self-infliction.⁶

Although there are not many studies that have delved into the investigation of internal wound paths,^6,8,9 some considerations regarding the possibility of identifying self-inflicted bullet paths according to the site of the entrance wound have been proposed⁹:

- Gunshots to the right temple: Suicides commonly exhibit a bullet wound path moving from front to back and upwards, or without significant inclination on the coronal and on the transverse plane.

- Gunshots to the left chest: Suicides typically shoot from right to left, or without significant inclination on the sagittal plane, while homicidal paths often move from left to right.

- Gunshots to the mouth: Suicides typically aim upwards, with downward pathways being rare, as observed in other studies.

- Gunshots to the back of the head or neck: If a suicide occurs in this uncommon location, the path usually moves upwards, whereas, in homicides, paths can occur in any direction.

The reason for this lies in the fact that suicidal individuals often strive for a stable and comfortable positioning of the shooting hand, aiming for a lethal outcome with the gunshot. Consequently, the geometric interplay between the body and firearm tends to establish distinctive firearm positions and characteristic wound paths typical of suicide cases.⁹

However, the presence of a single discharge is not exclusively indicative of suicide, as multiple shots are also observed targeting various body regions, including vital areas. Nonetheless, a suicide hypothesis remains viable if the firing distance aligns with self-infliction.⁶

Commonly targeted sites include the temple (typically right, except in left-handed individuals), the precordial region, the mouth, and the forehead.^6,10,11 Inaccessible locations for self-infliction usually discount the suicide hypothesis.¹² Carrara et al. noted that in suicide cases, the firing distance and location often reflect the deliberate preparation of the victim, who consciously adopts a stable and adequate position to carry out the act. This contrasts with homicides, where the victim's posture and actions are often influenced by defensive reactions or attempts to evade the assailant.¹³ Characteristic signs in suicide cases also include soot deposition on the back of the hand of the shot victim holding the weapon and a minor injury between the thumb and forefinger of the same hand.^8,13 In contrast, firearm homicides do not conform to specific patterns regarding injury location, number, firing distance, and wound path direction. The assailant's actions are significantly influenced by unpredictable external circumstances (e.g. the victim's defensive reactions, aiming errors, interventions by others).^10,14 Hence, injury patterns are varied, and only frequent characteristics are recognisable.^10,14 The firing distance in homicide exhibits variability. Contact shots suggest an “execution” style and are often found in the head. Conversely, close-range shots are highly indicative of murder, often exhibiting secondary effects such as burning, soot deposition, and tattooing.^6,8 Bullet wound paths reflect the victims’ positions at the time of impact.^8,13 The weapon is typically not found at the death scene as the perpetrator tends to take it away,^6–8 but- based on our experience - a firearm may be discovered at the crime scene in specific scenarios (e.g. impulsive killings, crimes of passion, or simulated suicides). However, even when the firearm itself is not recovered, detailed examination of the recovered projectile(s) and/or cartridge case(s) usually allows reliable inference of the weapon's caliber and general type, thus providing essential context for interpreting internal bullet wound paths.

This study aims to report the demographic, circumstantial, and autopsy data of cases involving suicide and homicide from rifled weapon discharge present in our archive, with a particular focus on the analysis of the observed differences in internal bullet wound paths between these two distinct circumstances.

Materials and methods

Data collection

A retrospective analysis was conducted on autopsy reports from the Section of Legal Medicine at the University of Rome Tor Vergata, spanning January 2007 to October 2022. Initial screening excluded deaths unrelated to rifled weapon discharge wounds. The inclusion criteria for case eligibility were a complete autopsy execution and the availability of a police investigation report containing circumstantial data and witness testimonies. Each case received a unique identifier, linked to the manner of death. As only one accidental case was identified, it was omitted from the analysis. Each case was so categorised as either suicide or homicide. A data extraction sheet was developed recording:

- Demographic and circumstantial data (age, gender, nationality of the victim, discovery site of the body and firearm, firearm type, victim-perpetrator relationship in homicides, psychiatric history, and motive).

- Autopsy findings (number of bullets discharged per victim, presence or absence of exit wounds, signs of a struggle, traumatic non-firearm-related wounds, entry and exit wound distribution, macroscopic characteristics of entry wounds, secondary shot signs, estimated firing distance, affected internal organs, internal bullet wound path).

Fatal and non-fatal shots were differentiated based on internal injuries. Superficial wound distribution was represented via 26 anatomical regions, akin to Lupi Manso et al.'s method for sharp force injuries.¹⁵ Bullet path reconstruction followed anatomical body planes as suggested by Gitto et al.⁶:

- Sagittal plane: leftward (L), rightward (R), or neutral (/);

- Transverse plane: downward (D), upward (U), or neutral (/);

- Coronal plane: backward (B), frontward (F), or neutral (/).

Demographic, circumstantial, and autopsy findings, as well as bullet pathways, were described using frequencies and percentages.

Results

The study included 64 cases: 36 suicides and 28 homicides. As previously mentioned, one additional case - a man who accidentally shot himself in the thorax while showing and cleaning his handgun in front of witnesses - was classified as accidental and thus excluded from the analysis, as accidental shootings were not considered in this study.

Demographic and circumstantial data

Table 1 summarises the results. The missing data resulted from incomplete police reports. Of the total, 84.4% of the victims were male. Ages ranged from 17 to 92 years, with the suicide group averaging 15 years older. In one case, a male found deceased in a lake remained unidentified, preventing age and nationality determination. The most common location for homicide victim discovery was public streets (42.9%), contrasting with a single occurrence of suicide. In suicide cases, the weapon was found at the death site in 91.7% of instances. Weapon type differences between groups were not statistically significant due to frequent missing data in homicide cases (i.e. the firearm not being found at the crime scene, etc.).

Table 1.

Demographic and circumstantial information distributed according to the manner of death.

		Suicide	Homicide	Total
Sex	Males, n (%)	33 (91.7%)	21 (75%)	54 (84.4%)
Sex	Females, n (%)	3 (8.3%)	7 (25%)	10 (15.6%)
Age	Years, mean ± s.d.	54.3 ± 18.8	40.9 ± 13.3	48.45 ± 17.8
Nationality	Italian, n (%)	34 (94.4%)	25 (89.3%)	59 (92.2%)
	Not-Italian, n (%)	1 (2.8%)	3 (10.7%)	4 (6.3%)
	- Albanian, n (%)	0	2 (7.1%)	2 (3.1%)
	- Romanian, n (%)	1 (2.8%)	1 (3.6%)	2 (3.1%)
	N.A.	1 (2.8%)	0	1 (1.6%)
Location of victim's body	Home, n (%)	24 (66.7%)	9 (32.1%)	33 (51.6%)
	Street, n (%)	1 (2.8%)	12 (42.9%)	13 (20.3%)
	Other, n (%)	8 (22.2%)	3 (10.7%)	11 (17.2%)
	- Car, n (%)	5 (13.9%)	2 (7.1%)	7 (10.9%)
	- Public Park, n (%)	1 (2.8%)	0	1 (16%)
	- Lake, n (%)	1 (2.8%)	0	1 (1.6%)
	- Hospital, n (%)	0	1 (3.6%)	1 (1.6%)
	- Schools, n (%)	1 (2.8%)	0	1 (1.6%)
	Workplace,n (%)	2 (5.6%)	4 (14.3%)	6 (9.4%)
	N.A., n (%)	1 (2.8%)	0	1 (1.6%)
Location of weapon's discovery	Near the victim, n (%)	21 (58.3%)	0	21 (32.8%)
	Handed over to Police, n (%)	0	8 (28.6%)	8 (12.5)
	Victim's right hand, n (%)	7 (19.4%)	0	7 (10.9%)
	On victim's body, n (%)	5 (13.9%)	0	5 (7.8%)
	All Others, n (%)	0	4 (14.3%)	4 (6.3%)
	- Author's home, n(%)	0	1 (3.6%)	1 (1.6%)
	- Author's right hand, n (%)	0	1 (3.6%)	1 (1.6%)
	- Near the author, n (%)	0	2 (7.1%)	2 (3.1%)
	N.A., n (%)	3 (8.3%)	16 (57.1%)	19 (29.7%)
Type of weapon	Semi-automatic pistol, n (%)	28 (77.8%)	9 (32.1%)	37 (57.8%)
	All Others, n (%)	5 (13.9%)	3 (10.7%)	8 (12.5%)
	- Revolver, n (%)	2 (5.6%)	2 (7.1%)	4 (6.3%)
	- Automatic pistol, n (%)	1 (2.8%)	0	1 (1.6%)
	- Rifle, n (%)	0	1 (3.6%)	1 (1.6%)
	- Flobert gun, n (%)	1 (2.8%)	0	1 (1.6%)
	- Crafted weapon, n (%)	1 (2.8%)	0	1 (1.6%)
	N.A., n (%)	3 (8.3%)	16 (57.1%)	19 (29.7%)
Belonging to armed group	Yes	5 (13.9%)	5 (17.9%)	10 (15.6%)
Belonging to armed group	No	31 (86.1%)	23 (82.1%)	54 (84.4%)

Psychiatric background and motive

Suicide group

Data were available in 20 cases (58.3%). Major depressive disorder was diagnosed in 11 cases, followed by 3 cases of anxiety-depressive disorder. One of the victims had previously attempted suicide. Five cases had no known psychiatric disorder. Chronic diseases were the most common motive (9 cases), followed by romantic disappointments (8 cases), psychiatric disorders (4 cases), terminal cancer (3 cases), and workplace issues (2 cases).

Homicide group

In 24 cases (85.7%), the relationship between victim and offender was known. Most were friends or acquaintances (10 cases), followed by romantic relationships (5 cases), and other family ties (4 cases). In 3 cases, the individuals involved were strangers, with 2 related to organised crime. Motives included romantic disputes (10 cases), trivial reasons (6 cases), settling of accounts (4 cases), economic motives (3 cases), and homicides committed during other crimes (3 cases).

Autopsy findings

The mean number of shots was three times higher in homicides (1.06 ± 0.232 in suicides vs. 3.61 ± 3.06 in homicides). The total number of bullets discharged in suicides was 38, with 94.7% involving only one bullet (36 out of 38), leaving only 2 cases with non-fatal shots. In 28 homicide cases, 51 out of 101 projectiles discharged were deemed fatal. Additionally, 4 re-entered the victim, resulting in a total of 55 entry wounds in fatal shots.

Fatal shots

The distribution of entry and exit wounds of fatal shots in homicides is presented in Figure 1. For suicides, as expected, there was a much narrower distribution: only 3 anterior regions were involved (72.2% in the right side of the head; 16.7% in the oral region; 11.1% in the left hemithorax), with no entry wounds located in the posterior body region. Predominantly, brain and cranial injuries were observed in suicides (88.9%). In homicides, most injuries were to the lungs (62.7%) and non-cranial bones (60.8%). Great vessel (13.7%), liver (7.8%), and spinal cord (3.9%) injuries appeared only in homicides. Small differences in heart injuries were noted (11.1% in suicides vs. 17.6% in homicides). Table 2 presents the major differences in frequencies of the anatomical distribution of external wounds and internal injuries. Table 3 presents the frequencies of firing distance, secondary shot signs, and macroscopic features of entry wounds in the two circumstances. Table 4 details the analysis of internal bullet wound paths.

Figure 1.

Anatomical distribution of entrance and exit wounds of fatal shots in homicides. (a) Entry wound. (b) Exit wounds.

Table 2.

Major differences between suicide and homicide in anatomical distribution of external wounds and internal organs injuries in fatal shots.

	Suicide	Homicide
Entrance wounds (total)	(36)	(55)^a
Head, right side, n	26 (72.2%)	2 (3.6%)
Head, left side, n (%)	0	7 (12.7%)
Left Hemithorax, n (%)	4 (11.1%)	19 (34.6%)
Exit Wounds (total)	(29)	(36)
Head, left side, n (%)	22 (75.9%)	1 (2.8%)
Dorsal region, n (%)	2 (6.9)	15 (41,7%)
Interna organs injuries, (number of bullets that hit the victim)	(36)	(51)^a
Brain and skull, n (%)	32 (88.9%)	12 (23.5%)
Other bones, n (%)	1 (2.7%)	31 (60.8%)
Lungs, n (%)	1 (2.7%)	32 (62.7%)
Great vessels, n (%)	0	7 (13.7%)

4 out of 51 re-entered the victim.

Table 3.

Range of discharge, secondary signs and shape of entrance wounds in fatal shots, according to the manner of death.

	Suicide (36)	Homicide (51)
Range of discharge
CONTACT, N (%)	28 (77.8%)	0
- Strict contact, n (%)	17 (47.2%)	0
- Loose contact, n (%)	11 (30.6%)	0
CLOSE DISCHARGE, N (%)	8 (22.2%)	28 (54.9%)
- between 3–5 cm and 10–15 cm, n (%)	7 (19.4%)	4 (7.8%)
- between 10–15 cm and 30–40 cm, n (%)	1 (2.8%)	6 (11.8%)
- between 30 and 50 cm, n (%)	0	18 (35.3%)
SHORT TO MID-RANGE DISCHARGE (from 50 up to 100 cm), n (%)	0	21 (41.2%)
MID- TO DISTANT-RANGE DISCHARGE (>100 cm), n. (%)	0	2 (3.9%)
Secondary firing signs
Skin laceration/Splitted edges, n (%)	14 (38.9%)	0
Muzzle impression, n (%)	6 (16.7%)	0
Burning, n (%)	1 (2.8%)	0
Soiling, n (%)	5 (13.9%)	3 (5.9%)
Powder tattooing, n (%)	1 (2.8%)	6 (11.8%)
Other – more than one secondary sign, n (%)	6 (16.7%)	1 (2.0%)
- Splitted edges + muzzle impression, n (%)	3 (8.3%)	0
- Splitted edges + soiling, n (%)	0	1 (2.0%)
- Burning + muzzle impression, n (%)	1 (2.8%)	0
- Burning + soiling, n (%)	1 (2.8%)	0
- Burning + soiling + tattoing, n (%)	1 (2.8%)	0
No secondary signs, n (%)	3 (8.3%)	41 (80.4%)
Shape of entrance wounds
Ragged/stellar, n (%)	16 (44.4%)	0
Oval, n (%)	5 (13.9%)	22 (43.1%)
Circular, n (%)	15 (41.7%)	29 (56.9%)

Table 4.

Bullets woundpaths in fatal shots according to the anatomic planes of the body and combined pathways.

Suicide (36) n (%)	Anatomic planes	Homicide (51) n (%)
	Sagittal plane:
33 (91.7%)	Leftward, n (%)	13 (25.5%)
3 (8.3%)	Rightward, n (%)	37 (72.5%)
0	Parallel, n (%)	1 (2.0%)
	Coronal plane:
2 (5.6%)	Frontward, n (%)	14 (27.5%)
34 (94.4%)	Backward, n (%)	35 (68.6%)
0	Parallel, n (%)	2 (3.9%)
	Transverse plane
20 (55.6%)	Upward, n (%)	16 (31.4%)
16 (44.4%)	Downward, n (%)	35 (68.6%)
0	Parallel, n (%)	0

Suicide (36) n (%)	Combined pathways	Homicide (51) n (%)
14 (38.9%)	LDB	9 (17.6%)
1 (2.8%)	RDB	17 (33.3%)
17 (47.2%)	LUB	0
2 (5.6%)	RUB	8 (15.7%)
0	RDF	7 (13.7%)
0	RUF	5 (9.8%)
1 (2.8%)	LDF	1 (2.0%)
1 (2.8%)	LUF	1 (2.0%)
1 (2.8%)	/DB	1 (2.0%)
0	LU/	1 (2.0%)
0	RU/	1 (2.0%)

L: leftward; R: rightward; D: downward; U: upward; B: backward; F: frontward; /: parallel.

Non-fatal shots

In suicides, non-fatal shots (2 in total) affected the palm of the left hand, likely accidental. Figure 2 shows the distribution of entry and exit wounds of non-fatal shots in homicides. Regarding internal injuries, 33 out of 55 shots affected only subcutaneous and muscular tissues, 10 caused bone fractures (excluding the skull), and 2 bullets injured the liver, one also affecting a kidney. The firing distance was always greater than 30–40 cm, with 78% shot beyond 50 cm. 96.2% displayed no secondary shot signs. The combined wound paths can be summarised as follows: RDF 34%, RUF 24%, RDB 14%, RUB 12%, and LDB 10%. The remaining 6% comprised varied combined pathways unique to individual cases.

Figure 2.

Anatomical distribution of entrance and exit wounds of non-fatal shots in homicides. (a) Entry wound. (b) Exit wounds.

Discussion

In our series of 64 rifled-weapon fatalities (36 suicides and 28 homicides) the two manners of death displayed clear quantitative and qualitative contrasts. Female victims represented 3.3% of suicides and 25% of homicides. The mean age was 54.3 years in suicides and 40.9 years in homicides. Suicide victims were discovered at home in 67% of cases and inside their own car in 14%, whereas homicide scenes were more dispersed: 43% on public streets, 32% in private dwellings and 25% in other settings. The firearm was recovered at the scene in 91.7% of suicides—still in the victim's hand in one fifth of these—whereas in 57% of homicides the weapon was never found. Law-enforcement officers were the shooters in 15.6% of all cases (six homicides and four suicides).

Data available for suicides showed major depressive disorder in 70% of cases with an established psychiatric; chronic or terminal illness emerged as the leading motive (44%), followed by romantic distress, psychiatric anguish and work-related problems. Among homicides with known motives, romantic disputes predominated (36%), followed by trivial arguments, settling of accounts, economic conflicts and crimes of opportunity.

Gun-usage patterns differed sharply. A single shot occurred in 95% of suicides, while homicides averaged 3.6 shots per victim and 61% of the deceased sustained multiple wounds, often displaying overkill features. Entry-wound distribution was highly concentrated in suicides: 90% involved the head—72.2% in the right temporal region and 16.7% in the oral cavity—and 10% the precordial area; no chin wounds were observed. Homicides displayed twelve different entry sites, dominated by thoracic wounds (44.5% overall, 34.6% on the left side); posterior entry wounds occurred only in homicide victims and accounted for one third of all homicide shots.

Internal injuries mirrored these external patterns. Fatal suicide shots injured the brain in 88.9% of cases, whereas homicide shots more frequently damaged lungs (62.7%) and non-cranial bones (60.8%); 13.7% of homicide bullets injured great vessels. Every thoracic suicide shot perforated the heart, one quarter also affecting the lungs, while only one quarter of thoracic homicide shots were limited to the heart. No suicide shot originated beyond 30–40 cm from the body surface and contact or near-contact entry wounds occurred exclusively in suicides. Conversely, 80.4% of homicide wounds lacked secondary firing signs. Entry-wound morphology differed likewise: suicides produced predominantly rounded or ragged holes, whereas homicides more often showed oval, oblique-angle entries.

Our bullet wound paths analysis (Table 4) yielded the following key findings:

Sagittal plane: In cases of homicide, paths from left to right were observed in 72.5% of cases. This may correlate with the prevalence of right-handedness, influencing the interaction dynamics between offender and victim. Suicides more commonly exhibited paths from right to left due to the high frequency of gunshot wounds to the right temporal region. A left-to-right path in the anterior region requires further ballistic analysis to determine the relative positions of the shooter and victim.

Coronal plane: The most significant discriminant was paths directed from back to front, which are rarely observed in suicides. In two cases of suicide, this path resulted from gunshot wounds to the right temporal region, likely due to the angle of the hand at the time of firing. Aside from this specific scenario, the study suggests that a back-to-front path strongly indicates homicide, particularly when circumstantial evidence excludes complex or unusual suicide setups.

Transverse plane: Homicides displayed downward paths more frequently, possibly due to defensive actions by the victim, resting postures (e.g. sitting), or the dynamics of a physical altercation. Suicides rarely presented this pattern.

Combined pathways

- In suicide cases, the most frequent combined paths were:

From right to left, bottom to top, and front to back (LUB - 47.2%), which was exclusive to suicides.

From right to left, top to bottom, and front to back (LDB - 38.9%).

- In homicide cases:

The most frequent path was from left to right, top to bottom, and front to back (RDB - 33.3% of cases), observed in only one suicide case.

Exclusive to homicides were pathways directed from left to right and back to front (RDF and RUF), regardless of inclination on the transverse plane.

The LDB pathway (from right to left, top to bottom, and front to back) was observed in both suicides (38.9%) and homicides (17.6%). According to the present study, without additional contextual data, this pathway could present interpretive challenges, particularly in cases of entry wounds in the left hemithorax, which is a common site for both suicide and homicide.

Some limitations of the study should be considered when interpreting its findings. Firstly, the relatively small sample size may limit generalizability. Excluding accidental firearm deaths might have obscured internal-path patterns relevant to broader forensic contexts. Reliance on retrospective data and incomplete police reports sometimes hindered full reconstruction of circumstances. Finally, although directional analysis is informative, it cannot by itself establish the manner of death; integration with autopsy, ballistic and scene evidence remains essential.

Comparison with previous researches led to the following considerations. In our study, female victims constituted 3.3% of suicides and 25% of homicides. This mirrors earlier suicide series yet exceeds the homicide proportions reported in Chicago⁶ and Bari.¹⁰ Our mean ages (54.3 y in suicides, 40.9 y in homicides) accord with Chicago (USA)⁶ and older UK¹⁶ and Turkish¹⁷ data but interestingly diverge from Bari (Shoutern Italy).¹⁰ Suicide scenes centred on the home, reflecting UK¹⁶ and Finnish¹⁸ trends; homicide scenes were heterogeneous, as noted by Druid et al.⁸ Recovery of the firearm was rare in homicides, echoing prior observations.^6–8,19 The 15.6% share of police-related shootings differs from the risk pattern described by Violanti et al.²⁰ Our 70% prevalence of major depressive disorder in suicides aligns with global figures.^21,22 Romantic motives drove 36% of homicides, surpassing Italian^10,23 and international^24,25 rates. Overkill exceeded the 25–53% range observed in Germany,⁹ the UK,¹⁶ Norway²⁶ and the USA.²⁷ Thoracic predominance in homicides contrasts with head-dominant series⁶; posterior-head entries highlighted by Blumenthal et al.¹¹ were absent here. Posterior entries overall, and cardiac-only suicide injuries, reinforce patterns noted by earlier authors.^6,14 Firing distance also differed: while Stone et al.²⁸ suggest that contact entry wounds do not preclude homicide, in our sample, they were observed only in suicides. In line with this, no suicide cases had shots indicative of firing distances over 30–40 cm. Consequently, the absence of additional firearm wound features strongly suggests homicide (80.4% of homicide cases vs. 3.3% of suicides), especially if the wound is oval shaped, not rounded, which suggests that the bullet struck the body at an oblique angle instead of perpendicularly. Such angled entries typically result from unstable shooting conditions, where the shooter or the victim is moving—a dynamic far more common in homicide scenarios. In contrast, suicides usually involve static, self-inflicted shots, fired in stable conditions with direct alignment between weapon and target, leading to rounded entry wounds.

Direction of bullets’ internal pathways as diagnostic indicators for homicide versus suicide has been minimally explored in literature.^6,8,9 In both instances, as the same anatomical regions may be affected, exclusive reliance on entry wound location is insufficient to determine the manner of death. Indeed, in both homicide and suicide, the intent is often to target vital regions to ensure lethality. However, a key differentiating factor lies in the dynamics of the shooting event. Suicidal acts typically occur in calm, controlled environments, with the subject in a static and deliberate position, which results in straight, well-aligned wound paths and rounded entry wounds. In contrast, homicides frequently involve physical struggle or movement, leading to unstable firing conditions, angled shots, and more variable wound paths, often with oval-shaped entry wounds.⁶

This is represented in our study also with the analysis of the results regarding non-lethal discharges, which are comparable in number to lethal ones (51 vs 50) in homicide cases, but with a more differentiated distribution, with even greater involvement of the posterior regions of the body and significant involvement of the lower limbs.

Future research should enlarge multi-centre datasets, include accidental cases and employ imaging or experimental reconstructions to validate complex combined paths such as LDB, thereby refining forensic practice and strengthening medicolegal conclusions.

Conclusion

This study highlights significant differences in bullet pathway patterns between suicide and homicide cases, particularly concerning the anatomical planes and combined pathways. Suicides were characterised by wound paths that were more consistent and aligned with self-infliction, such as leftward and upward pathways, while homicides displayed greater variability, including distinctive patterns such as back-to-front or downward pathways. The findings emphasise the importance of integrating autopsy results with circumstantial evidence and ballistic investigations to improve diagnostic accuracy in distinguishing between manners of death. Future research could further refine the forensic applications of internal bullet wound path analysis, aiding in more robust medicolegal determinations. Nonetheless, internal wound path direction must always be interpreted in conjunction with autopsy findings, scene analysis, and ballistic data, as it cannot independently determine the manner of death.

Footnotes

Author note

The guarantor (AM Tavone) accepts full responsibility for the work, had access to the data and controlled the decision to publish.

Contributorship statement

AMT conceived and designed the study, collected and analysed the data, and drafted the manuscript; RV retrieved and curated the case files and contributed to data cleaning; GC collected the data, performed ballistic wound-path assessments and verified data accuracy; GPi prepared tables and figures, and analysed the data; GPe conducted the literature review and assisted in interpreting the findings, FG collected the data, and assisted in data interpretation; NR collected the data and carried out the initial critical revision and integrated reviewer feedback; GG performed statistical summaries, and led the secondary manuscript revision; GLM supervised the project, provided strategic guidance and approved the final manuscript.

Data availability statement

Data available on request due to restrictions e.g. privacy or ethical. Data presented in this study are available on request from the corresponding author.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethical approval

The study was conducted in accordance with the Declaration of Helsinki. The present work is a retrospective analysis of completed forensic autopsy records. All personal data were previously anonymised and processed solely in aggregate form. Data usage for this purpose was authorized by judicial authority.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Guarantor

Alessandro Mauro Tavone.

ORCID iDs

Alessandro Mauro Tavone

Raimondo Vella

Giulia Ceccobelli

Naomi Romaniello

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