This cross-sectional study was conducted in the Department of Forensic Medicine, MKCG Medical College, Berhampur, Odisha, India, during a span of 10 years from 01-01-2006 to 31-12-2015 on 63 cases having an isolated fatal mechanical injury and 665 cases having multiple injuries over the body. The study is based on information in the documents (Inquest report and Dead body chalan) submitted by the investigating police at the time of autopsy of the dead bodies and the facts incorporated in the respective autopsy reports. Ethical approval was obtained from Institutional Ethical Committee.

Out of total 728 confirmed deaths resulting from homicide subjected to medicolegal autopsy, records of 63 cases having an isolated fatal mechanical injury and 665 cases having multiple injuries over the body were perused and were chosen as the study sample. By mechanical injury, we mean only those visible body damages produced due to breach in the natural continuity of the body tissues by application of mechanical force [4]. Homicidal deaths resulting due to non mechanical causes like poisonings, burns (both thermal and chemical) and drowning were excluded from the study group.

The data collected from the study sample were recorded in a case record form. While the first part of the case record form collected information on demographic details like gender, age, place and time of occurrence and number of assailants, the second part collected data on weapons used to cause the fatal injury, site of injury, mode of death. Detailed information regarding the circumstance of the crime was also sought from the police, victim’s relatives and friends.

The data collected was analysed using Graphpad Prism 5.0 free trial version. Descriptive analytical statistics was used to report the pattern, distribution and means of inflicting fatal isolated mechanical injury on the body. Chi-square test was used to analyse the dichotomous data summarized as proportions. A p-value of <0.05 was taken as statistically significant.

In the present study, it was observed that out of the total 728 established cases of homicide, 63 deaths were reported due to an isolated bodily injury. Majority, 52 of the victims died due to such injury were males. Thus, females were less predisposed to homicide (p=0.16).

Majority, 13 of the victims of isolated fatal injury were in the seventh decade whereas 185 of those with multiple injuries were in the fourth decade of their life. There was significant association between the age of the victims and the nature of fatal injury (p<0.01) [Table/Fig-1].

Sharp cutting weapons were used in 29 cases of isolated fatal injury and in 249 cases with multiple injuries. Kicks, blows or slap accounted in least number of cases accounting for 05 and 17 cases of isolated and those with multiple injuries respectively. There was significant association between the type of weapon and the nature of fatal injury (p=0.0168) [Table/Fig-2].

The most common site of isolated injury causing homicide was head involved in 26 cases. In multiple injuries on the body also the most common site of fatal injury was found on the head in 290 cases. The least common site of injury in isolated fatal cases and multiple injuries was the groin/scrotum in 05 and 13 cases respectively. A significant association was found between the site of injury and the nature of fatal injury (p=0.036) [Table/Fig-3].

The leading mode of death in this study was coma constituting 24 cases having isolated fatal injury and 287 cases having multiple injuries on the body showing a significant association between the mode of death and the nature of fatal injury (p=0.0019) [Table/Fig-4].

In the present study, isolated fatal homicidal injury were detected in 8.65% of cases. Mohanty S et al., of India have found that multiple assaults on the body in homicide were encountered in most (70%) cases [3]. It is pertinent to state here that multiple injuries in homicide are justifiable by the assailant’s clear intention and determination to kill. But the low quantum of isolated fatal injuries in homicide may be due to insufficient intention or lack of motive on the part of the assailant to kill. Sometimes the assailant may not necessarily want to kill the victim but may only have an intention to cause some bodily harm. Moreover, at other times the assailant may cause such bodily injury either in self defense or in an attempt to escape.

Most of the victims in this study were males clearly outnumbering the females with a male to female ratio of 4:1 and the maximum number of victims amongst the isolated fatal injury group were more than 60-year-old (20.63%) followed by 0-10 years (17.46%), whereas in homicides with multiple injuries, individuals in the fourth decade (27.81%) followed by fifth (26.61%) and third (24.96%) decades respectively are most commonly affected [Table/Fig-1]. Edirisinghe PA et al., of Sri Lanka detected male preponderance similar to this study [8]. Muhammad ZB et al., Mohanty S et al., Hilal A et al., of India, and Vij A et al., of Pakistan, Bhupinder S et al., and Kumar V et al., in a study conducted in Malaysia have found similar trends in the context of most common age group affected with respect to multiple injuries on the body causing homicide [2,3,9-12]. Meel B in a study done in African countries suggested male preponderance and common age group affected between 20-40 years [13]. High prevalence of isolated fatal mechanical injury among children and old individuals may be attributed to the fact that persons in their extremes of age are relatively weak in physical strength and incapable of imparting sufficient resistance. Moreover, a trivial isolated trauma in the extremes of age may sometimes prove to be fatal, thereby increasing the mortality as compared to the adult healthy counterparts.

Sharp cutting weapons were implicated in most instances in both isolated (46.03%) fatal homicidal injuries and with multiple (37.44%) injuries followed by hard and blunt weapons in 20.63% and 32.33% cases respectively. Death by strangulation, firing and kicks, blows or slap alone were encountered in a very small number of cases [Table/Fig-2]. In another study conducted in this Medical College by Mohanty S et al., sharp cutting weapons were implicated in 36.61% cases followed by hard and blunt weapons (24.41%) [14]. Similarly, sharp cutting followed by hard and blunt were the most common weapons in homicide in studies conducted by Kumar V et al., in Malaysia, Lee GM et al., of Ireland and Avis SP of Canada [12,15,16]. But studies conducted by Muhammad ZB et al., and Hilal A of Turkey, Marri MZ et al., of Pakistan and Eze UO et al., of Nigeria revealed that firearms were the most common weapon followed by sharp cutting ones [2,9,8,17]. The use of sharp cutting weapons as means of execution ahead of hard and blunt weapons is obvious and can be attributed to maximum lethality and easy availability than sophisticated weapons like firearms in this part of the world. However, the point of importance in this study are the 7.93% cases having isolated mechanical injuries in the form of kicks or blows or slap which turned fatal despite being non brutal in nature. This may be an indicator not only of the low degree of aggression but also the lesser magnitude of violence shown by the assailant. These injuries also suggest that the assailant had no intention to kill the victim.

In the present study, the head was the most common site involved both in isolated (41.26%) and multiple (43.60%) injuries followed by the neck in (31.74%] and (26.76%) cases respectively. Injury to the groin/scrotum was detected in 07.93% cases of isolated injuries [Table/Fig-3]. Studies conducted in other parts of India by Vij A et al., and Gadse S et al., are similar to findings of our study [10,18]. Study in Pakistan by Marri MZ et al., revealed injury to chest as the most common site, explained by common use of firearms [8]. However, another study conducted in this Medical College by Mohanty S et al., revealed majority of injuries were at multiple sites followed by injury to the head and neck [14]. Head and neck are the most common sites as they are the most vital and dangerous areas of the body where death is most likely by injury even if trivial. Few isolated injuries to the chest and abdomen were also fatal which were caused by firing or stabbing. In some cases (11.11%) isolated injury to the groin/scrotum were also implicated where death was due to neurogenic shock. Such injuries caused on the private part although dangerous is an indication of the assailant’s intention either to escape or render the victim temporarily incapacitated but does not substantiate his motive to kill or cause death.

The leading mode of death in isolated bodily injury causing homicide was coma constituting 38.09% of the cases followed by haemorrhagic shock in 34.92% of cases. Neurogenic shock (11.11%), asphyxia (7.93%) and vagal inhibition (7.93%) were the other modes of deaths [Table/Fig-4]. Almost similar observations were made in multiple injuries causing homicide also, but the incidences of death due to vagal inhibition were negligible (00.90%). Studies conducted on homicide by Vij A et al., Mohanty S et al., Padmaraj RY et al., Gupta S et al., Buchade D et al., and Gilani FN et al., suggested that haemorrhagic shock was the most common cause of death followed by craniocerebral injuries where coma is the mode of death [10,14,19-22]. The results of this study are different from that of others because the most common site of injury in this case is the head i.e., cranio-cerebral injuries where the mode of death is coma. However, in this study haemorrhagic shock as mode of death is not far behind. Again, in our study, vagal inhibition is found in quite a good number of cases in isolated injury causing homicide which is negligible in multiple injuries. It is one of the significant findings in terms of assessing the culprit’s intention or motive or determination to kill the victim. Deaths resulting from vagal inhibition may be a spontaneous outcome of trivial trauma not intended to cause death.

The study was confined within a particular geographical area. The study was based on information in the documents (Inquest report and Dead body chalan) submitted by the investigating police at the time of autopsy of the dead bodies and the facts incorporated in the respective autopsy reports. Scene of crime was visited only in very few cases.

In present study, we have found that homicidal deaths with isolated bodily injury showed a distinct pattern in comparison to homicides with multiple injuries. This study revealed that individuals in the extremes of their ages were the vulnerable. Easy access and high lethality make sharp cutting weapons the most widely used instruments for assault. The most preferred sites of assault were head and neck and even an isolated injury over these areas can prove fatal. Although most of the victims died due to coma, haemorrhagic shock, death due to vagal inhibition or neurogenic shock following injury to some sensitive sites like groin/scrotum cannot be discounted.

The outcome of the study is vital in the sense that there can be instances where the assailant has no intention to kill but injuries on the vital areas of the body may prove fatal by default. Careful evaluation of isolated injuries in homicidal deaths can be useful in predicting the degree of aggression, magnitude of violence and the determination or intention of the assailant to kill, thus assessing the culpability of the assailant in the crime. The Judiciary may also derive benefit in terms of differentiating between homicides amounting to murder from those not amounting to murder.