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When forensic evidence becomes contaminated

It is said that DNA evidence does not lie. However, human errors often cause flawed criminal investigations in Georgia. There are different ways that forensic evidence can be flawed and be used in favor of a criminal defense team.


Walking through or touching crime scenes is the most common method of ruining evidence. The bottoms of shoes and the tips of fingers can accidentally contaminate the components of blood, fingerprints, body fluids and other substances that are found at crime scenes. Another form of contamination is mixing DNA evidence from different people and confusing which suspect is which.

To prevent contamination, forensic investigators have to mark off areas where there are blood spills and stains. They have to block entries to crime scenes to prevent people from trampling through the evidence.

Lost or misplaced files

Forensic evidence sometimes gets lost when computer hard drives and portable disks become damaged in floods, fires or manmade disasters. Investigators who do not back up their computer data could lose all of the evidence that had been collected from the first day of the investigation and make a criminal case invalid.

Flaws can help the defense team

Flawed evidence is never admissible in court and can lead to a not guilty verdict or the reversal of a previous conviction. Although forensic mistakes are rare, the proof of mistakes is a powerful tool used in criminal defense.

The importance of sound evidence

The O.J. Simpson trial has proven that flawed forensic evidence can lead to an acquittal. The process of handling forensic evidence has to be undertaken with the greatest amount of caution. One mistake is used by a criminal defense team to acquit a client.