Today's jurors want absolute proof of a person's guilt before they'll take the person's freedom away. The jurors now want to see forensic evidence as proof. This has resulted in the further development of Forensic Science over the past couple decades, which has made the investigation of criminal cases increasingly complex for law enforcement officers in regard to the collection of evidence.
The use of the ever-evolving forensic science field has increased the number of Challenging Careers in Forensic Science, and though increased forensic science use has made the job of detectives more arduous and time consuming, investigators believe that the benefits of forensic science's use outweighs its increased and tedious burden on criminal investigators.
The most compelling use of forensic evidence appears to be DNA evidence, which can be used to identify a perpetrator - even decades after the commission of a crime. In its earlier days, DNA tests could take a couple years for the results to come back to investigators. However, today, investigators can receive DNA results much quicker, which helps them apprehend criminals in much less time. This swift removal of dangerous offenders from the streets often results in lives being saved, investigators believe.
Although forensic science was still in its early stages, Discovery Times' "The New Detectives" documentaries has said that a forensic odontologist was eventually able to make positive identification of serial rapist and murderer, Ted Bundy, by comparing impressions of his teeth to bite marks on one of his victims.
Bundy was executed in January of 1989. He had raped and murdered an estimated 40 or more women during the 1970s. The only physical evidence the intelligent and cunning Bundy left at the scenes of his crimes were bite marks on a Florida woman, which greatly helped prosecutors secure his conviction.
More recently, former football star, O.J. Simpson quickly became the prime suspect in the brutal murders of Nicole Brown Simpson and her friend, Ronald Goldman. The quick return of DNA tests allowed investigators to promptly arrest and charge Simpson with the June, 1994 murders.
During the commission of every crime, evidence is left behind (as well as taken from the scene) by perpetrators. Therefore, investigators must be trained properly in order to be effective in using forensic evidence to solve crimes. Their training allows forensic scientists to perform the necessary testing on evidence, which is not tainted or contaminated in any way.
In the Simpson case, the collection and handling of evidence had been called shoddy, among other things by defense attorneys according to "The New Detectives" documentaries. The mishandling of evidence was listed as one of the reasons for Simpson's acquittal in the case that has been called, The Trial of the Century. Therefore, it's possible that the use of forensic evidence can damage the prosecution's case as much as help it, if the evidence collection and handling is not done properly.
Further developments in Forensic Science, according to TruTV's, "Forensic Files" documentaries, are that today, fingerprints can be lifted from even more surfaces, including fabric. DNA evidence that was once only the human form, today can come from animal, plant, and bacteria sources. Imagine being linked to a crime by a virus that you have during the commission of a crime, or even evidence from a common cold!