The history of forensic science is very long and involved. It started from nothing and has been built up over the years to become the complex and advanced field it is today.
In any violent crime, it will most likely include blood, and a good amount of it. In the beginning, though blood might have been found, it was impossible to prove whether the blood was human or animal or who the blood even came from as there were no tests in place. Eventually, tests were introduced that could distinguish animal from human blood. Today, a sample of blood can be taken from a scene and using DNA, investigators can match the blood to the person it came from. DNA is also an important aspect of any crime. DNA samples can be tested hundreds of years after it has been found or taken from a scene. Many cold cases have been solved in the past years as DNA testing has become more advanced, and samples from years old cases have been taken from storage and retested. This can bring the criminal to justice and closure to the family of the victim whose murderer had been living free for years.
On the topic of ballistics, guns started out very rudimentary. At first they were slow to load and could only fire one shot at a time. After the shot had been fired, the gun had to be completely reloaded again, so they were seen as a waste of time even though they were quite deadly. However, as guns have changed and become more efficient, so have the methods used to identify the guns used in murder cases. As the barrel of a gun is shaved down and formed, scratches are left in it. These scratches leave unique grooves on a bullet, which can then be matched back to the gun it was fired from. This advancement was extremely helpful as investigators can identify who owns the gun that was used to kill or injure someone. Even if the owner has an alibi for the time of the crime, ownership of the gun can still provide clues to who had possession of it if not the owner.
Poisons were often used to kill someone because it left no violent marks on a body and the cause of death could be mistaken for a sickness. Arsenic used to be the most popular method of murder by poison because it is a colorless and odorless powder, and was untraceable using old methods. Over the years, tests for finding and identifying poisons have appeared. Today, a wide variety of poisons can be tested for and identified.
Forensic science has evolved over the years to become the advanced and involved field it is today. With the steps forward that have been made, forensic science helps immensely to bring criminals to justice.
Source: McCreery, Nigel. Silent Witnesses. Chicago: Chicago Review Press Incorporated, 2014. Print.