The orifice is generally a little smaller than the weapon.
A stab may sometimes present the appearance of an incised wound; the depth will, however, help to distinguish the one from the other. The wound may not at all correspond with the shape of the weapon, and the same pointed instrument may produce very different-shaped wounds in different parts of the body. Much depends upon the movement of the instrument in the action of puncturing; in the case of a double-edged instrument the wound will most probably be fusiform or diamond-shaped. When made with a knife the wound may be wedge-shaped if the knife have a thick back. A circular weapon splits the skin and leaves a slit; broken glass and pottery act in a similar way, but the wounds may have jagged edges and show signs of contusion in them. On dissection, two or more punctures may be found in the soft parts, with only one external orifice; these are due to the weapon being only partially withdrawn at each stab. Punctured wounds are always more dangerous than incised. They cause little, if any, hæmorrhage externally, unless a large vessel, such as the femoral artery, be injured, but they may cause internal hæmorrhage or penetrate a viscus, e.g. the lung or heart. These wounds generally heal by suppuration, and not infrequently an abscess is formed in and around the track of the wound. Perforating wounds generally have a large entrance wound with inverted edges, and a small exit with everted edges; if the weapon be rough, the reverse may be the case.
3. Lacerated and Contused Wounds
The edges of these wounds are never smooth, and generally do not correspond at all with the weapon. A considerable amount of contusion or bruising surrounds the solution of continuity of the part. Hæmorrhage from these wounds is usually slight. A point of considerable interest may arise in connection with this class of wounds; the defence may declare that the injury was the result of a fall, and not due to a blow. The history of the case, and the presence of a bruise where no theory of a fall can explain its existence, will often afford the only solution of the difficulty. Lacerated wounds heal by suppuration, generally with more or less sloughing, and leave a permanent scar. Scratches with the finger-nails may be considered as lacerated wounds, but the skin is merely abraded, not divided. They are never important as wounds, but often as a proof of a struggle in cases of rape, &e. Bites are also lacerated wounds. The diagnosis of lacerated and punctured wounds, whether inflicted before or after death, will depend on much the same grounds as those of incised wounds, hæmorrhage, vital reaction, &c.
Table of Differentiation Between
Ante-mortem and Post-mortem Wounds:
4. Gunshot Wounds
The appearance which gunshot wounds present will to a great extent depend upon the form of the projectile, and the distance at which the firearm was discharged. Round halls make a larger opening than conical. Small-shot, fired within a short distance of the body, make one large ragged opening. The scattering of the shot depends on the calibre of the gun, on the charge of powder, and essentially on the distance. A charge of ordinary (No. 5) shot, to make a single hole, must have been fired at less than one foot; but experiments should always be made with the alleged weapon. A patent cartridge would make a single hole at a considerable distance—five or six yards. Round bullets may split, but the conical ones seldom do. The edges of wounds produced by the discharge of firearms are always more or less ecchymosed; this condition appears in about an hour after the infliction of the injury. If the ball strikes obliquely, the edges of the wound may be much lacerated, or the opening may be valvular and of small size, if the skin over the part be in any way tightened, or if a conical ball has been used. The injury to bones is greater from conical than from round balls. The old round balls were easily deflected; the conical are not so easily turned aside. The track of the ball widens as it deepens. This is the reverse of an ordinary punctured wound. The ball may either lodge in a part, or perforate it. Should it have lodged, it must be preserved and compared with the alleged firearm. Bits of clothing or wadding may be carried into the wound. The latter should be carefully kept, as they may prove important as a means of identification.
The aperture of entrance and exit must, if possible, be determined. On this point there is much difference of opinion. The wound of exit is always smaller than the wound of entrance (Casper). In this opinion Casper agrees with M. Malle, Olliver d‘Angers, and M. Huguier, but is opposed by Taylor, M. Matthysens, and others. “The characters of a gunshot wound,” says Assistant-Surgeon Neill, “are those of a contusion and laceration of all the tissues. Sometimes they are so simple as to bear resemblance to a punctured wound, particularly if a rifle-ball (conoidal), revolving on its long axis, has passed through the soft parts at a great speed, but within a few hours it resembles a contusion. The wound of entrance, as it has been termed, bears no comparison in size or shape to that of the exit when a rifle-ball has caused the injury. In the former you see the edges of the wound curving inwards, and the circumference small, with little or no hæmorrhage. In the latter, the wound is large, with torn and irregular edges projecting outwards, and perhaps only slight oozing of blood. In a short time, averaging an hour, round the entrance wound slight redness begins, gradually extending to about two inches round its orifice. Again, this colour changes to a blue- or greenish-black, and you see all the appearances of a severe bruise, with a small wound of the skin, its edges still curved inwards. In the exit wound the discoloration of the skin is not apparent.” The probable reason for the discrepancies in the statements of observers, as to the characters of entrance and exit wounds, may be found in the fact that experiments have been conducted with different-sized balls, different kinds of weapons, with varying quantities and qualities of the powder used, the character of the wads, and with varying velocities and distances. As pointed out by M. Roux, the two openings may be equal if the ball preserves the same velocity through the tissues as it possessed before entrance; the entrance hole is smaller than the exit, when the ball has lost much of its trajectile force, and enters the softer parts of the body first; the entrance is larger than the exit, when the ball first enters through the denser tissues of the body, and leaves through the softer.
The opening of entrance made by the ball has generally, but by no means always, inverted edges. The edges of the exit opening are everted, bloody, and raw; but both the entrance and exit wounds may be everted in fat persons, due to the protrusion of the fat; and this eversion may also result from the expansive power of the gases generated during putrefaction, should this condition be present. Wounds made by double shots, as from double-barrelled guns, or pistols, or from slugs fired from one barrel, diverge after their entrance into the body.