WAS THE INJURY INFLICTED BEFORE OR AFTER DEATH?
This is a question which may often be asked in cases of fatal injuries, and it is one which must be answered as definitely as we are able, for the defence may rest on the assertion that the wound or injury was post mortem and not ante mortem. What are the means we have to enable us to answer the above question? The most important factor is the condition of the blood and the changes that it undergoes after death. For some hours after death the body retains its animal heat. As long as this is retained rigor mortis does not set in and the blood is more or less fluid. This period varies, but on the average it does not last longer than eight or ten hours. Before this time, however, the blood has begun to undergo certain changes. These changes result in the inability of the blood from a post-mortem wound to coagulate completely. At first the greater part may coagulate, but after a time coagulation is less and less complete, and the coagula are not as firm as those from the blood of a living person. The period at which these changes occur also varies, but they may generally be clearly noticed in from three to four hours after death, or even sooner. In the first two to four hours after death, therefore, as far as the condition of the blood is concerned, it may be difficult or impossible to say whether a wound was made before or soon after death. In other words, this difficulty exists as long as the tissues of the body live after the body as a whole is dead.
There are certain general pathological or occasional conditions of the body in which the blood during life does not coagulate at all or only imperfectly, as in scurvy and in the case of the menstrual blood. Also blood in a serous cavity, especially if it be abundant or there exists inflammation, is found not to coagulate or only imperfectly. Post mortem the blood remains liquid long after death in cases of death by drowning, asphyxia, etc., and in such cases hemorrhage may be free in a wound made some time after death. Furthermore, after putrefaction has set in the blood again becomes more or less liquid, and may flow away from a wound like a hemorrhage, but it no longer coagulates.
The principal signs of a wound inflicted during life are (1) hemorrhage, (2) coagulation of the blood, (3) eversion of the lips of the wound, and (4) retraction of its sides.
1. Hemorrhage varies in amount with the size of the wound, the vascularity of the part, and the number and size of the large vessels involved. In incised or punctured wounds the amount, as a rule, is quite considerable. If there is a free exit most of the blood runs off; the rest stays in the wound, where it soon coagulates with the exceptions mentioned above. But besides partly filling the wound in the form of a clot, the edges of the wound are deeply stained with the coloring matter of the blood, and this stain cannot be removed by washing. This staining involves especially the muscular and cellular tissues.
Further, a hemorrhage during life is an active and not a passive one; the blood is forced into the interspaces of the tissues in the vicinity of the wound, and is found infiltrated in the cellular tissue, the muscles, the sheaths of the vessels, etc. It is here incorporated, as it were, with the tissues so that it cannot be washed away. In an ante-mortem wound the arterial nature of the hemorrhage may show by the marks of the jets of blood about the wound or on the clothes or surrounding objects. When a large vessel has been divided and the exit for the blood is free, this may run off without infiltrating the tissues or even staining the edges to any considerable extent, and there may remain but little in the wound. In the case of lacerated and contused wounds the amount of hemorrhage is less, but rarely fails entirely, and if the wound is in a vascular part it is liable to cause death from hemorrhage, though a whole limb may possibly be torn off without much hemorrhage. In the latter case, however, there are usually found clots of blood adhering to the edges of the lacerated wound and the ends of the vessels. In contusions where there is no wound of the skin the blood is prevented from flowing externally, and its accumulation and distribution form an ecchymosis. Here again we see the active power of the hemorrhage which infiltrates between the tissues, stains them deeply, and appears either as a mere stain or in fine clots incorporated, as it were, with the tissues or partly occupying a cavity formed by an extensive displacement of the surrounding parts. The amount of blood varies under the same conditions as in incised wounds, and also according to the greater or less disintegration of the tissues by the blow, allowing a larger or smaller central cavity to be formed. In “bleeders” the amount of the hemorrhage does not vary under the normal conditions, but a fatal hemorrhage may occur from a very insignificant wound. After hemorrhage from a wound made during life the veins are empty about the wound, especially those situated centripetally, while normally after death the blood is mostly aggregated in the veins. They are the source of post-mortem hemorrhage, but do not empty themselves to any great extent.
The hemorrhage from a wound made after death may be extensive if the blood remains fluid as in the cases mentioned above, i.e., after death from drowning or asphyxia or after the commencement of putrefaction. Otherwise the amount of hemorrhage decreases with the length of time after death, until the blood loses its fluidity and hemorrhage no longer occurs. In general, it is slight unless a large vein is opened, for the veins are the source of the hemorrhage. There is usually scarcely any hemorrhage after the first two to four hours. This applies also to subcutaneous hemorrhages or ecchymoses. These post-mortem hemorrhages are passive and not active, consequently there is less infiltration of blood into the surrounding tissues, which merely imbibe it, and the stain is less deep and may be washed off the edges of the wound, in contrast to the stain of ante-mortem wounds. After putrefaction has set in the hemorrhage may be more abundant, as the blood is driven to the surface by the formation of gas in the abdomen and thorax. At the same time, the coloring matter of the blood transudes through the walls of the veins and is imbibed by and stains the tissues, so that it may be impossible to distinguish it from a true ecchymosis. Fortunately these conditions are of small moment, as an examination is seldom deferred so long.
Cadaveric ecchymoses show almost invariably while the body is still warm and the blood more or less liquid, i.e., during the first eight or ten hours after death. They are not due to injury or violence before or after death, but they may closely resemble ecchymoses produced on the living body and be mistaken for them. This is the more important as they are quite constant on the cadaver.
In this connection, it may be said that an ecchymosis due to a blow before death may not show till after death, as it requires some time for a deep ecchymosis or even an ecchymosis covered by a thick layer of skin to show superficially. Thus a man kicked in the abdomen died thirty-five hours after the injury from peritonitis, due to a rupture of the bladder. No ecchymosis appeared at the site of the injuries until after death. It is not uncommon in cases of hanging to observe an ecchymosis along the course of the cord appearing only after death. Huize met with a case of this description. Devergie remarked that on the bodies of those drowned ecchymoses are often hidden for a time on account of the sodden state of the skin, and they appear only after the water has evaporated, which may require some days. Furthermore, it is not necessary to survive long after an injury in order that an ecchymosis may show post mortem. If the blood is fluid at the time of the blow and any capillaries or larger blood-vessels are torn, then we may have an ecchymosis though death be almost instant. Casper thought that it required some time before death for an ecchymosis to develop, and that if the person injured by a contusion died soon after the injury, an ecchymosis would not appear after death. There are many well-authenticated cases to prove that Casper’s opinion is wrong. Among the most famous of these is that of the Duchesse de Praslin.[615] She was attacked and killed by her husband while she was asleep in bed. The thirty or so wounds showed a mortal conflict, and she could not have survived more than one-half hour, and yet after death there were numerous ecchymoses from the contusions.
Another case is also mentioned by Taylor.[616] A young man died suddenly after a blow from a companion, having been struck in the side a fortnight before by a heavy box, which knocked him senseless and nearly killed him. The post mortem revealed an ecchymosis on the side which on the authority of Casper’s opinion was attributed to the old injury. The color of the ecchymosis would be sufficient to settle all such doubts, as the changes of color would have fully developed or the color even disappeared in part in fourteen days’ time.
An ecchymosis made post mortem does not undergo the color changes seen in ecchymoses during life, unless the tissues are œdematous in which the ecchymosis occurs. These changes in color have already been described, the deep blue changing to violet in eighteen to twenty-four hours at the earliest. In support of the foregoing and disproving Casper’s views, Christison found that within two hours after death severe blows on a dead body are followed by a livid discoloration, similar to those produced by a blow shortly before death. This livid discoloration is due to the effusion of a very thin layer of blood external or superficial to the true skin, sometimes in a stratum of the true skin or more rarely into the cellular tissue, staining deeply the partition walls of the fat-cells. Of course, a more or less recent contusion or ecchymosis on a dead body was not necessarily produced at the same time as the cause of death. It should be borne in mind in this connection that ecchymosis is not a necessary result of a blow or contusion.
According to Devergie, ecchymosis does not appear when a blow inflicted post mortem is received by skin directly covering a bony surface beneath, and rarely appears where there is a large amount of fat and no solid point of resistance beneath the site of the blow.
We have already referred to the fact which Portal long ago remarked, namely, that the spleen has been ruptured without ecchymosis or abrasion of the skin. The same absence of ecchymosis has been noticed in cases where the liver, stomach, intestines, bladder, etc., have been ruptured as the result of contusing blows.
The following case cited by Taylor[617] illustrates this point. Henke reported the case of a man who died of peritonitis a few hours after fighting with another man. There was no mark on the skin or ecchymosis, though there existed peritonitis from rupture of the small intestine. The blow was proven by direct evidence, and though some medical witnesses on account of the absence of external signs thought that no blow could have been struck, others of more experience admitted that it could have been the cause of the rupture.
Watson[618] reports a similar case of a girl nine years old who received a blow from a shoe on the abdomen. This was followed by great pain, collapse and death in twenty-one hours. No marks of injury were visible externally, but peritonitis existed from rupture of the ileum.
A similar case is reported by Williamson,[619] where peritonitis resulted from complete rupture of the ileum without any trace of injury externally, though the blow was struck by the hoof of a horse.
Another case was brought into Guy’s Hospital[620] who had been run over by an omnibus. No injury was discoverable, though the wheel had passed over the chest and abdomen. He died of peritonitis, however, which set in on the second day, and on post-mortem examination the liver and small intestines were found ruptured.
Christison thought as the result of his experiments and experience that the most reliable signs of an ecchymosis made during life, and distinguishing it from one caused by a blow after death, were as follows: The skin of the ecchymosed area is generally much darkened and discolored from blood infiltrated through its entire thickness; the skin is also much firmer and more elastic from swelling of the part if the contusion is received some hours before death. But we may have an effusion beneath and not in the substance of the skin, and the above signs might possibly be due to an injury inflicted only a few minutes after death. The above signs may therefore be absent, and when present are not absolutely indicative of an injury received during life. In general, the effects of severe contusions inflicted soon after death may closely resemble those of slight contusions received during life.
There is little danger of contusion if the blow be inflicted on a dead body after the loss of body heat and the beginning of rigor mortis.
2. Coagulation of Blood.—As stated at the beginning of this section, blood from a wound inflicted during life coagulates with the exception of that from those suffering from certain pathological or occasional conditions or in certain locations, already mentioned. This coagulation is not immediate, but is complete in about five minutes. The entire amount of blood lost is thus coagulated and the coagula are firm. These coagula (if the wound is not interfered with) occur in the opening of a wound and on its edges, especially at the mouths of the blood-vessels, which are thus plugged. The blood which infiltrates the interspaces of the tissues is coagulated in the form of these interspaces. The same is true of the blood of an ecchymosis whether there be a hematoma or only an infiltration between the tissues, or both. These clots represent more or less the form of the space occupied by the blood. In the case of the scalp a subcutaneous clot may be mistaken for a depressed fracture of the skull from the fact that the edges of the clot become very hard while the centre is still quite soft. A wound in which a large artery has been divided may present very little clotting in the wound if the opening is free and the blood has mostly escaped in a jet.
In a wound produced soon after death there may be some clotting, but less in amount, firstly, because there is less hemorrhage, and, secondly, because not all the blood clots. These conditions increase with the length of time after death, so that after a time a wound made on a cadaver would show very little if any clotting owing to very slight hemorrhage, and little or no clotting of the blood extravasated. When the body has lost its animal heat and rigor mortis has begun to set in, then there is no more coagulation of the blood and no more hemorrhage, under normal conditions, for the blood has mostly become clotted in the vessels of the body. Consequently, with the exception of wounds inflicted very soon after death, we can distinguish an ante-mortem from a post-mortem wound by the condition in which the blood is clotted. If there is any hemorrhage, the wound being inflicted before the loss of animal heat and the blood remains entirely fluid on the surface or in an ecchymosis, we know that the wound was produced after death and some hours after death unless any of those conditions exist in which the blood does not normally coagulate. If the hemorrhage is slight or quite moderate in amount and venous in character, if the blood is only clotted in part and the clots are rather soft and do not form a plug at the mouth of each artery, and especially if the staining of the walls of the wound can be washed off, then the wound was probably produced post mortem, but not so long after death as in the first case supposed. If the characters of the hemorrhage and the clotting are still more like those normal to a wound inflicted during life, then, as a rule, it is impossible to say from these two features of the wound, hemorrhage and clotting, whether the wound was inflicted during life or a very short time after death.
3. Eversion of the Lips of the Wound.—The edges or lips of a wound inflicted during life may be inverted, instead of everted, if a thin layer of muscular fibres is attached directly to the deep surface of the skin, as is the case in the scrotum. The eversion of the edges of the skin is due to their elasticity, and ceases to occur as soon as the skin loses its vitality. Consequently eversion ceases to occur soon after death, within a very few hours. A wound in which the edges are neither inverted or everted was therefore inflicted after death. If this sign is present and marked, the wound was inflicted during life or within two or three hours or less after death. If this sign is present but very slightly marked, the wound may have been made even somewhat longer after death.
4. Retraction of the sides of the wound is also dependent on their vitality and ceases to occur when this is lost a few hours after death. In the retraction of the edges of the wound we have all the parts involved, but unequally. The muscles, arteries, skin, and layers of connective tissue all retract, varying in the degree of retraction according to the order in which they are named. In different parts of the body this comparative order of retraction is liable to more or less variation. Every surgeon is familiar with this retraction of the tissues, which necessitates certain rules in the technique of operations, especially of amputations. Muscles retract the more the longer they are and the farther the incision is made from their attachment. Without specifying a definite time, we may say that, as a rule, this retraction lasts no longer than about two hours after death, consequently when it is absent we may infer that the wound was inflicted two hours or more after death. The amount of retraction grows less and less after death for about two hours, after which it is very slight if it occurs at all, owing to the loss of elasticity of the tissues. This sign is especially useful in the case of a mutilated body where, by examining the degree of retraction of the muscles, we may infer whether the mutilation was done before or after death. The sides of a cut made on the cadaver are comparatively smooth and even, owing to the absence of the unequal retraction of the various elements, which makes the surfaces of a gaping ante-mortem wound uneven and irregular. Relying on these circumstances in the “affaire Ramus,” cited by Vibert,[621] one was able to recognize the order in which the body had been mutilated.
Other minor signs of a wound inflicted during life may be briefly mentioned. If the edges of the wound are swollen, or show signs of inflammation or gangrene, or if pus or adhesive material is present on the edges of the wound, we may infer that the wound was inflicted some little time before death. Of course, if cicatrization has commenced, some days must have elapsed before death after the wound was received. If the blow causing a contusion was inflicted some time before death, there will be more or less of a general swelling of the region, partly due to the blood effused, but also partly due to œdema.
It is not always easy to say whether a fracture was produced while the body was living or dead. If the body was still warm when a post-mortem fracture was produced there is little difference from an ante-mortem fracture, except that there may be a little less blood effused. In a fracture produced after rigor mortis has set in there is little or no blood effused. In the case of fractures the presence of callus, indicating the process of repair, shows that the accident occurred during life, and, as we have already seen, we may form some idea of the length of time elapsed between the injury and the time of death. On the cadaver it is said to be harder to cause fractures and lesions of the skin than on the living body. Casper says that fractures of the hyoid bone and the larynx are impossible after death, and he also was not able to rupture the liver or spleen.
In distinction to the characteristic signs of a wound inflicted during life, we may mention briefly some of the signs of post-mortem wounds when the wound has been inflicted from two to ten or twelve hours or more after death:
(1) The hemorrhage is slight in amount and may fail altogether.
(2) The character of the hemorrhage is venous, corresponding to the source of the hemorrhage from the veins, the arteries being nearly empty after death.
(3) The edges of the wound are not deeply stained, and this staining may be removed by washing. The spaces between the tissues are not infiltrated with blood.
(4) The blood remains either entirely fluid or, if there are clots, these are softer than those in an ante-mortem wound, and only a portion of the blood is thus clotted. There are no clots plugging the open mouths of the arteries on the surface of the wound; the veins may or may not be closed by an imperfect clot.
(5) The skin of the edges is not everted or inverted.
(6) The sides of the wound do not gape and their surfaces are smooth and even, as the tissues are not unevenly retracted.
Résumé.—It is very easy from the foregoing to distinguish between a wound inflicted before death and one ten or twelve hours after death.
If the hemorrhage has been abundant and arterial, if it has infiltrated between and deeply stained the tissues and the stain cannot readily be washed off; if the blood coagulates completely and the coagula are firm and are found lying in the wound, plugging the vessels, and incorporated with the tissues between which they lie; if the edges of the skin are everted and the sides of the wound are retracted and uneven—under these circumstances, we may be sure that the wound was inflicted during life or a very short time after death. If, on the contrary, the hemorrhage is slight in amount or almost fails altogether; if it is venous in character; if the edges of the wound are only stained by imbibition of the blood, which is not infiltrated between the tissues, and the stain may be washed off; if the blood is not at all or only slightly clotted and the clots are soft; if the skin is not everted and the sides of the wound are smooth and lie nearly in contact; if there are no clots plugging the divided arteries on the surface—then we need have little hesitancy in saying that the wound was produced after death, but probably not later than ten or twelve hours after death. If the wound was inflicted still longer after death and before putrefaction, then we would have a lack of the signs due to hemorrhage, clots, staining, etc. If we find the conditions more or less midway between the first two, we may be left in some doubt as to the date of the injury. Thus if the hemorrhage is moderate, the blood mostly but not altogether clotted and the clots moderately firm, the skin slightly everted, and the sides slightly separated and not altogether smooth on their surface; if the surfaces are fairly deeply stained and the stain cannot be easily washed off—then we can only say that the wound was inflicted during life or within two hours or so after death, and this fact is often enough for the purposes of the medico-legal inquiry.
The same is the case with contusions where there is no bleeding externally. If we have a bluish, violet, green, or yellow tumor with or without more or less superficial œdema; if this tumor fluctuates or is hard, but in either case is elastic; if on incision the skin and the tissue spaces are infiltrated with blood which is coagulated, or if there is a cavity filled with clotted blood, the coagulum being firm and the entire amount of blood coagulated—then the wound was inflicted during life. If, however, the surface shows a bluish or violet color, little or no swelling of the skin, which is of natural thickness, and the ecchymosed area is not tense and elastic to the touch; if further the blood is found on incision to be fluid or if coagulated only partly so, and the blood is not infiltrated into the tissue spaces, but merely imbibed by the tissues—then the blow was inflicted after death, and probably more than two or three hours after.
In contusions especially we may have difficulty, as the sign of fluidity of the blood may fail and putrefaction may modify the conditions of the wound unless parts deep beneath the surface be examined.
We see, then, that in some cases it is very easy to say that a wound was inflicted post mortem. If a wound was not inflicted until ten or twelve hours after death or even sooner, we cannot easily mistake it. But in many cases it may be hard or impossible to say whether a wound was inflicted during life or within an hour or two after death. Here we must be cautious in expressing an opinion which should be guarded. But we should remember that it is important to be able to state that a wound was inflicted before or immediately after death, as no one but a murderer would think of inflicting a fatal injury on a body immediately after death. In such cases a well-guarded medical opinion may often meet all the requirements of the case.
Granted that a given wound was produced before death. There are, then, one or two questions which may arise, and which depend for their answer on the length of time the wounded person could have lived and the physiological or muscular acts which he could have performed after receiving the injury and before death. The first of these questions may be expressed as follows:
Could the Victim have Performed Certain Acts after having Received his Fatal Injury? The term “certain acts” here refers to almost any thing or things which would require time and strength—in other words, the continuance of life with bodily and mental powers for a certain time after receiving a mortal injury.
This question may be raised in relation to an attempted alibi of the accused, who may have been proved to be in the presence of the victim a moment before death. If after this moment the victim has moved from the spot or performed certain acts before death, the attempted alibi may depend upon the answer to the question as to whether the given acts of the victim were compatible with the fatal character of the wound. An alibi can aid in the acquittal of the accused only when the nature of the injury was such that death would be supposed to be immediate or nearly so. Great care should be taken on the part of the medical witness in answering this question, for after very grave wounds, proving speedily fatal, the victim sometimes can do certain acts requiring more or less prolonged effort, as shown by numerous examples. Wounds of the brain are especially noticeable in allowing a survival of several hours, days, or even weeks, during which time the injured person may pursue his occupations. Where the survival has lasted days or weeks, the alibi has no importance, but not if the survival is of shorter duration. The following case is cited by Vibert[1] and may be mentioned in this connection, though the wound was caused by a bullet which traversed from behind forward the entire left lobe of the brain. After the injury the victim was seen by several witnesses to climb a ladder, though with difficulty, for he had right-sided hemiplegia. He was found insensible more than half a mile away, and did not die until six or eight hours after the injury. Severe injury of important organs is sometimes not incompatible with an unexpectedly long survival. Devergie cites two illustrations of this which are quoted by Vibert.[622] A man received several extensive fractures of the skull, with abundant subdural hemorrhage, and rupture of the diaphragm with hernia of the stomach. The stomach was ruptured, and nearly a litre of its contents was contained in the left pleural cavity. Notwithstanding all this, he was able to walk about for an hour or so and answer several questions. He died only after several hours. Another man, crushed by a carriage, received a large rupture of the diaphragm, complete rupture of the jejunum, and rupture and crushing of one kidney. Yet he walked nearly five miles, and did not die until the next day.
More rarely wounds of the great vessels are not immediately fatal. M. Tourdes is quoted by Vibert[623] as citing the case of a man who descended a flight of stairs and took several steps after division of the carotid artery; also of one who lived ten minutes after a bullet-wound of the inferior vena-cava.
Even wounds of the heart are not as speedily fatal as is commonly supposed, and often permit of a comparatively long survival.
Fischer[624] found only 104 cases of immediate death among 452 cases of wounds of the heart, and healing occurred in 50 cases among 401. Vibert[625] mentions two striking cases of long survival after wounds of the heart. A woman received a stab-wound which perforated the right ventricle, causing a wound one centimetre long. She did not die until twelve days later, when on autopsy there was found an enormous extravasation of blood in the left pleural cavity and pericardium. The second case, though one of bullet-wound, is equally applicable and instructive in this connection. A man received a bullet-wound which perforated the left ventricle, the bullet being found later in the pericardium. After being wounded he threw a lamp at his assassin which set fire to the room. He then went into the court-yard, drew some water, carried it back in a bucket, extinguished the fire, and then lay down on his bed and died.
In studying the wounds of different regions of the body, we may find many other mortal wounds which, though speedily fatal, leave the possibility of more or less activity before death. We see, therefore, that even in those wounds which are commonly supposed to be immediately fatal, even by many medical men where attention has not been called to the exceptions, such exceptional cases are not uncommon in which death is not immediate. Time and even strength may thus be allowed for more or less complicated activity. An alibi cannot, therefore, be allowed without question on the part of the medical expert, who must exercise great caution in expressing an opinion. The second question which may sometimes arise in connection with the last, but having little to do with the subject of this section, is the following:
How Long before Death had the Deceased Accomplished Certain Physiological Acts? For instance, how long after a meal did he die? This is hard to answer with precision, as digestion varies with the individual, and digestion begun during life may go on to a certain extent after death. We may be able to say if digestion has just commenced, is well advanced, or has terminated. What was eaten at the last meal may be learned by the naked eye, the microscope, the color of stomach contents and their odor. The state of the bladder and rectum is sometimes called in question. All the above facts have less bearing on the case than those in relation to the former question.