Biological evidence can often be challenged
Back when the mob ruled the criminal empires in the country and saying ‘sleeping with the fishes’ was commonplace, the technologies that were used by investigators and prosecutors were a lot less advanced than the technologies used today. One of the main advances that investigators and prosecutors rely on today is DNA.
DNA evidence is some of the strongest evidence that can be used because of the overwhelming accuracy. Interestingly, DNA evidence can also be used to exclude someone during an investigation if that person’s DNA isn’t found on any of the evidence pertaining to the crime.
In some cases, DNA evidence from a crime scene points law enforcement officers right to the person who committed the crime. That is usually only possible if the person already had a DNA profile from a previous DNA sample in a database.
In other cases, the DNA evidence at a crime scene is collected, but there aren’t any matches in the database. If police officers have a person of interest and are able to obtain a DNA sample, they could compare the DNA from the crime scene with that sample.
Despite the accuracy of DNA evidence, there is still room for improvement in the systems used for analysis and collection. That leaves room for defendants to question the evidence.
Challenging DNA evidence isn’t something that a novice should attempt. Instead, if a DNA challenge is in order, it might be necessary to call in expert witnesses who can attest to the claims that are being made. Getting this aspect of defense moving early in the case is often necessary to ensure that everything is in place when it is needed.
Source: United States Department of Justice, “Advancing Justice Through DNA Technology: Using DNA to Solve Crimes,” accessed Oct. 21, 2015