Introduction Hanging is the most common method of suicide in Malaysia according to the National Suicide Registry Malaysia statistics of 2009

Introduction
Hanging is the most common method of suicide in Malaysia according to the National Suicide Registry Malaysia statistics of 2009.1 However, hanging in combination with suicidal ligature strangulation is uncommon. A ligature strangulation case should be considered as homicide unless proven otherwise. This article reports of a suicidal strangulation by ligature coupled with hanging. The deceased had no previous medical or psychiatric disorder. He accomplished self-strangulation using a shoelace and hanging by a HDMI cable. Scene assessment and post-mortem findings concur with suicide. This report describes an unusual case of suicidal ligature strangulation in combination with hanging using two different ligatures.

Case report
The deceased is a 31 year-old man of Chinese ethnicity, who is unmarried and lived with his parents in a double story house. His education level was that of a diplomate and he worked in a metal company. He was last seen alive was at 8.00 pm after coming home from dinner with his parents. On the next day, at about 3 pm, his father realising that his son was not yet awake and decided to wake him up, only to discover that his room door was locked from the inside. Having had no response after several knocks on the door, the parents decided to break into the room. They found their son suspended from the ceiling with a HDMI cable (Figure 1). The police upon receiving the information had attended to the scene and brought the body down by cutting the HDMI cable. There was a ladder next to him which is believed to have been used by the deceased to tie the cable to the ceiling. There were no pornographic material or other sexual paraphernalia found in the room. The room although appeared to be unkempt, did not present with any evidence of a struggle. Death was confirmed by the attending paramedics before the body was transported to the mortuary by the police for a post-mortem examination.
A post mortem examination was carried out on next day, with an estimated post mortem interval (PMI) of 38 hours from the time he was last seen alive. External examinations revealed that rigor mortis was releasing and fixed hypostasis was present at the back and lower limbs (Figure 2). There were marked facial congestion and moderate petechial bleeding on the conjunctivae and skin of the face which were sharply demarcated by the strangulation region. The hanging ligature mark at the upper part of the neck which was consistent with the HDMI cable was present as a linear furrow measuring 1cm wide. This parchmented abrasion was found to be directed towards the back of the ears before waning off at the level of temple on both sides. Just below the cable ligature mark, three loops of a shoe lace ligature were present on the neck. A single knot was present on the front and double knot at the back of the neck (Figure 3). The ligature marks were present in the form of a continuous patterned horizontal groove which completely encircled the neck: the mean width of 0.5 cm but measured 1.5 cm at the anterior aspect of the neck. (Figure 4). Internal examination of the neck revealed small haemorrhages of bilateral sternocleidomastoid muscles. There were no laryngeal cartilage or hyoid bone fractures. No other evidence of injury was noted other than a moderate pulmonary oedema. Post mortem toxicology was negative. Cause of death was ascertained as neck compression due to ligatures.

Discussion
Suicide is increasing in numbers globally, with hanging being one of the most common way to end one’s life.2 The constricting force around the neck is derived from the gravitational force of the body weight. Death in suicidal ligature strangulation occurs when a constant force is maintained around the neck to obstruct venous blood flow.3 Polson demonstrated that a force of only 3.2 kg is necessary to occlude arterial vessels, whereas a force of 2 kg is enough to occlude a venous system.4 Thus, a simple ligature like an elastic band can produce death by strangulation as has been reported in literature.5 Determination of the manner of death in cases of ligature strangulation is a challenge to crime investigators and forensic pathologists. Ligature strangulation is mostly homicidal, and suicidal ligature strangulation is relatively rare. The task to differentiate a self-strangulation from a homicidal strangulation is onerous, given the fact that there are no particular characteristic features to distinguish one from the other.6 As the case in hand presents with the deceased found in his own room with the door being locked from the inside, with the absence of evidence of violence, the scene findings were in favour of suicide.
There have been cases of suicidal ligature strangulations reported previously. Three such literatures have described no fractures of hyoid bone or thyroid cartilage but minimal haemorrhage of the strap muscles.7-9 This was in contrast with one case described by Demirci et al, in which there was a fracture and ecchymosis of the left upper horn of the thyroid cartilage.10 Given the findings of the case in hand, the shoelace had left a more prominent mark compared to the HDMI cable, together with the facial congestion and conjunctival patechiae which may point in favour of a homicide. However, the internal findings revealed that other than the trivial haemorrhages of the sternocleidomastoid muscles, the laryngeal cartilage and hyoid bone were left uninjured, which is congruous with suicide. Fixed post-mortem lividity mainly in the lower limbs and forearm is suggestive that the body was suspended in a prolonged vertical position after death.11 This is also consistent with the timeline derived from the investigation report.
In 1961, Polson identified several presumptive techniques of suicidal strangulation.4 Later, various authors presented suicidal ligature strangulation cases describing methods similar to that with some modifications.8,12,13 Neither multiple ligatures nor repeated knotting is strongly indicative of homicidal action.6 The use of more than one ligature as well as multiple turns, up to 20, have been repeatedly reported in suicides. This case presents with similar findings, whereby there was a shoelace which had two turns around the neck, coupled with a HDMI cable used for the act of suspension.

Localisation of the knot is crucial to determine whether the knot is reachable by the deceased. Analysis of literature showed that the posterior position of the knot is very rare in suicidal strangulation.6 Therefore, the self-strangulation technique in the case in hand is unique compared to previously reported cases. The anterior knot is an overhand knot produced by crossing two ends of a ligature over each other in the front.14 It is unstable in nature unless the ligature has a rough texture. The posterior knot was a figure of eight knot on top of overhand knot. This knot stabilised the ligature. Both the knots can be made by the deceased himself. Therefore, in this case, the ligature strangulation could be suicidal.
On the other hand, the application of a tight ligature around the neck is a general finding in homicidal strangulation which warrants a thorough examination to confirm or refute that as the manner of death.4 However, in the absence of any homicidal circumstances, it is also possible for the deceased to apply a tightly fastened ligature around the neck fixed by a figure of eight. A reasonable reconstruction of this event is that the deceased first could have tied the shoelace tightly at the back of the neck after crossing at the front. He had then hung himself with the HDMI cable which was tied as a ligature on a hook at the ceiling. The underlying shoelace ligature fixed by a figure of eight knot was able to apply a constant pressure around the neck of the deceased, even after unconsciousness, to obstruct venous flow for enough time to cause cerebral hypoxia leading to death. Moreover, a negative toxicology result suggests full capacity of the deceased to accomplish the act of strangulation.

Conclusion
The present case emphasizes the importance and necessity of considering multiple available evidentiary issues to make conclusions about the manner of death. One single finding may not always definitively determine homicide or suicide in suspicious deaths. Analysis of number of ligatures, position of the knots, number of knots and turns, characteristics of ligature marks and the absence of defence injuries in ligature strangulations cases are crucial. Detailed documentation on the scene or in the autopsy room of these features is vital to differentiate between suicide and homicide. Questions as to whether the subject could reach the knot alone and possibility of self-inflicted lesions must also be addressed. In cases of ligature related asphyxia, documentation of characteristics of ligature and the knot tied is essential. Therefore, the noose should not be removed and the knots should be left intact. Proper coordination between the crime investigators and the forensic pathologist can provide a correct interpretation of the findings and clarify quickly the manner of death of these particularly complex cases.