forensic science - gsr trace essays

forensic science - gsr trace essays When an officer arrives at the location of an alleged shooting, after first rendering aid to the victim, he or she begins to search for evidence. Much of this effort consists of searching for the bullet, the gun, shell casings, and witness testimony; however, when the shooter leaves the scene, he/she takes with them a substantial part of the evidence that can significantly improve the prosecution's case. This evidence can be found on the hands, body and clothing of the shooter. Much of this evidence may be invisible to the naked eye, yet is still valuable for the prosecutions case. This evidence includes micro blood splatter, trace metal evidence, gunpowder residue, and even the gun. The first step when a suspect is apprehended in a shooting is to frisk the suspect for the weapon. While this will display that the suspect has a gun after the approach, it does not assist in the safety of the officer beforehand, nor assist in screening large quantities of people. Being caught with the proverbial smoking gun can be damning evidence in court, but typically at a crime scene, many onlookers gather making the frisking of each individual at the scene or leaving the scene an impossibility. In 1995, the Justice department funded a $2.5 million study for the development of a hand held device that would enable the officer to scan individuals at the crime scene for concealed weapons. These units will use one of three technologies to scan the clothed body for the presence of a weapon, the first would look for distortions in the electro-magnetic waves emitted by the human body, the second produces electro-magnetic pulses and measures the reflection differences presented by a weapon (much like traditional radar), the third detects differences in the Earth's electro-magnetic field as a weapon passes through it.1 These scanning devices will help make the first diagnostic step of the officer easier to identify who has a weapon at...