If there are lead residues the exhibit will go pink. It is then treated with hydrochloric acid, and it will go blue if there is lead present. A gun fired when in contact with an object will normally deposit a very intense ring of residue right around the edge of the bullet hole and the heat may melt synthetic clothing. A bullet fired from between 1 and 3 feet away tends to deposit a lot of residue, but most of it invisible to the naked eye. When there is no residue it could mean that the gun was fired from a long way away, or that there was something between the gun and the target.
Gunshot wounds See the medical section for information on the medical treatment of gunshot wounds.
This section is merely the forensic side of the subject. This can't be removed. If the gun was a few inches away there is a large ring of soot, since it had the space to desperse. It isn't embedded. If the gun was held at an angle, the ring of soot will be distorted in one direction.