Biological Evidence

 

When conducting a crime scene, time is always of the essence because the elements and the degradation of the sample of some evidence is crucially to collect before it is wasted. When dealing with blood samples for instance you have to careful not to contaminate it with anything else. Collecting it using sterile gauze or cloth is crucial and then placing it into a paper container will help make sure no moisture gets into the sample. If you were to place it into say a plastic bag the sample of blood will collect enough moisture to degrade it and contaminate it making the sample useless. Another such good piece of evidence is fingerprints. The method for collecting can vary from crime scene to crime scene. Many of which will use photography to collect the prints. However fingerprints arent always recognized by the naked eye some surfaces will make it almost invisible so to make it appear you use fingerprint powder such as black granular or aluminum flakes. Once the samples are shown they are then photographed or they use this sticky type clear paper to take the sample back to lab to analyze.