Most people know that forensics involves many different kinds of evidence, whether that is blood evidence or a weapon. However, the evidence can become degraded from a number of things such as time, heat or the use of bleach. Unfortunately, even advanced Forensic Techniques can be challenged by the use of a common kind of bleach found in many homes.
Chlorine bleaches can remove a Bloodstain to the naked eye but fortunately, forensics experts can use the application of substances such as luminol or phenolphthalein to show that haemoglobin is present. In fact, even if the shady criminal washed a bloodstained item of clothing 10 times, these chemicals could still reveal blood.
With oxygen bleach, the bleach has an oxidising agent, which could be a substance such as hydrogen peroxide. In these instances, haemoglobin is completely removed and can't later be detected. As expected, this presents a unique challenge for forensic scientists. Not only that, but it can significantly compromise an investigation and may mean that Evidence is not properly investigated and used in a trial.
Forensics experts will not examine and check for important DNA Evidence until they have initially found an appropriately identified blood sample. In this way, the entire investigation is compromised and the opportunity to obtain more information is lost.
Fortunately, there is a better chance of obtaining useful information from the seams of clothing. While washing does remove a great deal of evidence in the rest of the garment, it is far more challenging for a criminal to remove evidence found in the clothing seams.
Yet, science can't always compete with materials used to remove these stains, such as oxygen bleach. However, it is at least a positive step that we can identify these challenges, which means that efforts can be focused on finding ways to overcome them and identify blood even after all kinds of bleaching. In the end, this is good news for forensics but bad news for criminals.
