Death by strangulation

Death occurs when a rope or similar object (cord) is wrapped around the neck and a force other than the deceased's body weight (the deceased's own hand, or a similar external force) is applied to the cord, tightening the neck (strangulation), resulting in death. Strangulation is when the death is the result of homicide, while self-strangulation is when the death is committed by suicide. In typical cases, the cord forms a roughly horizontal ring around the neck below the laryngeal prominence, generally leaving marks of equal depth (stranglehold marks). In the case of hanging, the pressure on the blood vessels in the neck is unbalanced and weaker than in hanging, where the deceased's own body weight is used to compress the neck, so the time to death is slightly longer than in hanging, and the face turns purple-red, there is significant swelling, and there are also small bleeding spots. Causes of death include compression of the airway and cervical blood vessels and nerves, but the primary cause is asphyxiation due to airway compression (closure or narrowing).

If the cord is applied with a force of more than 15 kilograms or is placed at the highest part of the neck, it will cause complete blockage of the trachea. The most common cause of death is strangulation, but self-stretching is not uncommon. Accidental deaths have also occurred due to the straps of luggage being tied around the neck. In cases of strangulation, fingernail marks from the victim's attempts to remove the cord are sometimes left on the neck. When the assailant is removing the cord, fibrous debris attached to the strangulation mark is important.

[Akiko Sawaguchi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

紐(ひも)など（索条）が頸(くび)に巻かれ、これに死亡者の体重以外の力（他人または自己の手、それに類する外力）がかかって頸部(けいぶ)が締められ（絞頸(こうけい)）死亡することで、首絞(し)め、絞首(こうしゅ)ともいう。他殺による場合が絞殺であり、自殺の場合が自絞死である。定型的な場合は、索条が喉頭(こうとう)隆起より下位頸部をほぼ水平輪状にかかり、一般に均等の深さの索条の跡（絞痕(こうこん)）を残す。絞頸の場合、頸部血管の圧迫は、自己の体重を利用して頸部を圧迫する縊頸(いけい)より不均衡で弱いため、死亡時間も縊死よりやや長く、顔面の紫赤色、腫脹(しゅちょう)、微小出血点も著しい。死因には、気道と頸部血管神経の圧迫がかかわるが、気道圧迫（閉鎖、狭窄(きょうさく)）による窒息が主因となる。

　索条が15キログラム以上の力で作用したり、頸部最上位にかかると完全な気管閉鎖を生じる。普通は絞殺が多いが、自絞死もまれでない。首にかけた荷物の紐による事故死もある。絞殺では、索条をとろうとした被害者の爪(つめ)跡がときに頸部に残る。加害者が索条を除去しているときは、絞痕付着線維屑(せつ)が重要となる。

［澤口彰子］

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