Collecting evidence from a crime scene is a crucial aspect of solving crimes. Before evidence can be seized, there must first be a court order approving the search of the crime scene and the seizure of the evidence found at the scene. Standard protocol for officers is for them to always use latex gloves, avoid plastic bags, double wrap small objects, package each object separately, and to collect as much evidence as possible. It is better to have too much evidence than to not have enough. There are countless amounts of evidence that can be found at a crime scene.
Blood stains are one type of evidence that can be found at a crime scene. Blood that is still in the liquid form should be picked up on a gauze pad. Once the blood is dried thoroughly it should be refrigerated and sent to the Laboratory (Andrus et al., n.d., para. 1). If the blood stain is found dried on clothing, the officer should wrap the piece of clothing in clean paper and place it in a sealed and labeled container. An object with dried blood stains needs to be sent to the Laboratory if it is small enough. If the object is too large to send, then using a clean knife the stain needs to be scraped onto a clean piece of paper, which then can be folded and placed in an envelope (Andrus et al., n.d., para. 2). When collecting autopsy blood samples, the officer should request that the pathologist obtain the sample directly from the heart and place it in a yellow or purple stoppered vacutainer. If the victim is still alive but in serious need of a blood transfusion, then the pre-transfusion blood sample needs to be obtained promptly before the hospital discards it (Andrus et al., n.d., para. 4). It is important for the Laboratory to receive all blood samples within 48 hours or the samples may be useless.
Another type of evidence that can be collected at a crime scene includes seminal stains. These are most commonly found on clothing, blankets, and sheets. Similar to liquid blood stains, seminal stains need to be air dried before being packaged and sent to the Laboratory (Andrus et al., n.d., para. 10). Victims in sex offense cases should always be examined by a physician. The physician uses a Sexual Assault Evidence Collection Kit to collect evidence directly from the victim.
Hair samples can also be found at crime scenes. Collecting hair can be made easier by using tweezers. The collected hair should be placed in coin envelopes then folded and sealed in larger envelopes. If hair is found attached to an object, the officer should leave the hair intact and package the entire object (Andrus et al., n.d., para. 13). In an attempt to collect the ideal 50 to 100 head hairs or 30 to 60 pubic hairs wanted for rape cases, the victim or suspect should bend over a large sheet of clean paper and rub their hands through their hair (Andrus et al., n.d. para. 15). The loose hair will fall out on the paper and can then be collected.
Collected fibers and threads are another type of evidence found...