The bullet or missile hitting the human body will first stretch the skin and penetrate into soft tissue or bone.After penetration of the bullet into the skin,the skin will partially return to its original position.Therfore,the entrance shot hole willbe smaller than the diameter of the bullet.The entrance shot wound will have dirt or smudge ring,carbon deposit & powder residues and abraded or contusion collar.

Firearms generally simulate contused wounds.Two wounds are generally produced by the impact of a single fire: (1)Wound of entry (2)Wound of exit. Firearm is any instrument or device able to propel a projectile by means of explosive gases generated by combustion of an explosive substance.

Mechanism of wound production: Direct effect of bullet is seen that is the permanent tissue loss along the local tract.The tissues are compressed ahead of the tract by a compression in the form of shock waves of spherical form so that tissue damage canbe produced in a considerable distance away from the original bullet tract.

The appearance of firearm wounds depends on the type of weapon,the nature of projectile fired(maybe shots,pellets,slugs or bullets),the distance of the firearm and the velocity of the bullet,the angle at which it strikes the body part and ricocheting of the bullet.

A ricocheted bullet deviates from its course by striking an intermediary object.Such bullets bruise the body surface or produce a gutter and then fall to the ground without entering the body.However,the bullet may enter the body in some cases.If ricocheting bullet hits bone after entering the body,there maybe extensive laceration of tissue.

A low velocity bullet can easily be lodged into body if it strikes a bone.At medium velocity ranges,the bullets tend to pass cleanly through the tissue and makes a clear hole through the bone.High velocity bullets fired at close range may fragment without striking any high resistant body(bone)causing extensive laceration of tissues.

The distance of muzzle of the firearm from the body maybe close or distant at the time of suicide,homicide or accident.On the basis of this distance wounds are classified into: (1)Contact shot wounds (2)close shot wounds (3)Near shot wounds & (4)Distant shot wounds. In a contact shot there is actual contact between the muzzle of firearm and the body part.Close shots are when the firarm is within the range of flame and powder blast of bullet or explosive material.A near shot is within the range of powder blast but outside the range of flame.

Sometimes there is no wound of exit seen on the body,it means that the bullet is still in the body.There couldbe other possibilities too, like it has been coughed out,lost in the vomit or feces in some specific conditions,or dropped out of the same hole as it had entered.

How can we tell if the wound is an entry or exit wound?Its easy to determine by observing the characteristics of a wound.One clear cut sign is that the entry wounds are smaller in size than the exit wounds.Other signs are that the entry wounds have inverted edges while edges are everted in exit wounds.A fat victim couldbe an exception as the entry wound in fat persons may show up with everted edges because of more body resistance presented.Furthermore, entry wounds have some exclusive characteristics:Abrasion or grease collar,burning blackening & singering,bleeding is generally slight while profus bleeding willbe seen in exit wounds,tract near the entry wound maybe bright pink due to carboxyhaemoglobin in near discharge, lead ring maybe seen on radilogical or chemical examination and clothing maybe turned toward or into entry wound.

Multiple entrance wounds and multiple exit wounds maybe observed sometimes.A single soft nosed bullet hitting a victim after ricochet can produce a number of entrance wounds.Tandem cartridge if used could result in multiple entrance wounds in a single fire.If the first bullet fails to leave the barrel and is ejected by the subsequent fired bullets,the bullets are ejected one before the other and are called as tandem bullets.

A single entrance injury may result in multiple exit wounds.It happens when a soft nosed or ricocheted bullet splits into several parts or in case of tandem bullets.