The analysis of gunshot residues on human tissues and clothing in suicide, homicide, suspicious death, or attempted murder events, permits the forensic scientist to confirm the possibility of an entry wound caused by a gunshot bullet from a pistol, revolver, rifle, etc. The residues to be detected are lead (Pb), antimony (Sb), barium (Ba) usually from the primer, copper (Cu) and zinc (Zn) usually from the metal jacket bullet and iron (Fe) possibly from the barrel of the gun used. The presence or absence of these elements and their relative concentrations can help in the interpretation of the event.