Wounds made by bits of glass and earthenware have irregular and uneven edges. Taylor[637] relates a case, Reg. v. Ankers (Warwick Lent Ass., 1845), where the wound was attributed to a fall on some broken crockery, but the wound was cleanly incised and the prisoner was convicted. As it may be alleged in defence that a given wound was caused by a fall on broken crockery or other substances capable of producing a punctured wound, it is important to notice whether the edges are lacerated and irregular or smooth and clean. The author quoted above cites another case which occurred to Watson, where the prisoner alleged that a deep, clean-cut wound of the genitals of a woman which had caused her death was due to a fall on some broken glass. The character of the wound disproved this defence. Another feature of such wounds, especially if they be deep in comparison to their length, is that they are very apt to contain small particles of the glass or earthenware which caused them. In fact, in all wounds it is well to search for any small fragments which will throw light upon the weapon used.
Wounds caused by scissors are often of characteristic shape. If the scissors were open we find two symmetrical, punctured diverging wounds, presenting more or less clearly the form of the blades of the scissors. If the blades have been approximated there is a triangular interval between the punctures, the apex of which is truncated if any skin remains between the punctures.
Lacerated wounds may not indicate the weapon used as clearly as punctured wounds, but the agent which produced them is often indicated by the appearance of the wound. They are generally accidental. But where they occur, as they not infrequently do, on the bodies of new-born children, they may give rise to the charge of infanticide. In some cases the weapon which caused the wound fits the wound produced, and thus important evidence may be furnished the prosecution. Taylor[638] cites the case of Montgomery (Omagh Sum. Ass., 1873), where a bill-hook which fitted the injuries on the skull of the deceased was found buried in a spot to which the prisoner was seen to go. These facts connected the prisoner with the weapon and the weapon with the murder. In other cases the wounds may be so lacerated or contused that the indications of the weapon are obscured.
Contusions and Contused Wounds.—The shape of a contusing body is sometimes reproduced by the contusion and the ecchymosis. Thus we are enabled to distinguish the marks of a whip, the fingers, the fist, etc. This is best seen when the ecchymosis is fresh, for soon the edges extend and the outline is less clearly marked. Plaques parcheminées, which we have already described as the marks of contused erosions, may show the form of finger-nails, etc. Contused wounds like simple contusions may show the shape of the weapon.
If the contusing body has a large area, the whole of this area cannot often strike the body at once, so that the outline of the contusion does not represent that of the weapon. But in general, severe contusions present greater difficulties than the preceding classes of wounds. We must generally be content if we can determine whether the wound was caused by a weapon, including the fist, or by a fall, and we are often unable to say even this. A fall is often alleged by the defence as the cause of the injury, but of course if the prisoner was responsible for the fall he is responsible for the results of the fall. If there are contusions or contused wounds on several parts of the head, or if the wounds are on the vertex of the head, it is presumptive of the use of weapons. We cannot often swear that each and every wound on the head was due to the use of a weapon. On the other hand, the presence of grass, sand, gravel, etc., in a wound is presumptive of a fall and of the origin of the wound in this manner. In case of a fall from a height the wound or wounds might be in almost any part of the body, on the vertex or elsewhere. Such a fall may be the result of accident, suicide, or murder. It is not unusual for female complainants to ascribe their wounds to a fall to exculpate the prisoner, especially if this happens to be her husband. We should remember that in the scalp or over the eyebrows a contused wound caused by a blunt instrument may resemble an incised wound. As already stated, however, if the wound is fresh careful examination will lead to a correct opinion, and the use of a sharp instrument may be disproved. If the wound is not recent there is great difficulty in judging of the cause. It is well to caution against accepting the interested statements of others in regard to the use of a weapon, unless the character of the wound bears them out very strongly. There may be a bad motive for imputing the use of a certain weapon to the assailant. It is far better to rely solely upon the evidence furnished by the wound in such cases.
It would be useful if we could lay down some general rules to discriminate between wounds caused by the blow of a weapon and those caused by falls, but this we are unable to do so as to cover all cases. Each case must be judged by itself.
If the question is asked which of two weapons caused certain contusions or contused wounds, we are still less likely to be able to answer it. In such a case we must make an accurate examination of the form of the wound and compare it closely with that of the weapon. In such cases also the second source of information on which we base our opinion as to the relation of a weapon to the wound may be of use, namely, the examination of the weapon. The presence of blood, hair, cotton or woollen fibres on one of two weapons indicates that this was the weapon used. The presence of blood is particularly to be looked for, and in those parts of the weapon from which it could be washed off least easily. We should further note the condition of the point and edge of the weapon, and if the edge is broken or nicked at all, whether this condition is old or recent. The sharpness of the edge should further be noted, and if the edge is sharp note whether it has recently been sharpened. All these points have a certain bearing on the case. Also the location, shape, depth, etc., of the wound should be carefully noted to see if an accidental fall would be likely to account for it. For these features of the wound may be such that no fall could cause it.
We see, therefore, that in incised and punctured wounds the use of a weapon may not be hard to make out, but that in general the question whether a particular instrument caused the wound is often difficult or impossible to answer. Often the best we can do is to say that the wound could have been produced by the weapon.