Forensic DNA Evidence and Wrongful Convictions
The use of deoxyribonucleic acid (DNA) profiling in forensics has exploded in recent years in the criminal justice system. The use of DNA profiling in forensics has had great success stories. Although DNA evidence can lead to a quick resolution in a case, it rarely happens. More often, DNA evidence is just another piece in a complex evidentiary puzzle, and it should be considered alongside other clues. Sadly, there are many times when DNA evidence found at a crime scene results in a wrongful conviction.
Breaking Down DNA
DNA is a protein code that programs how humans and animals grow and develop. All humans have DNA that is 99.9 percent identical to all other humans, but the remaining .01 percent makes us unique. We are genetically similar to our relatives by blood. The .01 percent of our DNA is used to generate a DNA profile. It resembles a graph, showing various peaks where our individual DNA is unique to us.
DNA profiles are frequently not clean enough to identify one person conclusively. Samples should exhibit 16 unique markers. When DNA is damaged by exposure to extreme temperatures or moisture before being profiled, the fingerprint generated will be deemed a partial profile and describe only one trait, such as their eye color. This makes it nearly impossible to conclusively identify someone from degraded DNA evidence. This evidence is likely to match up with numerous people in the federal database.
The Problem of Secondary Transfer
The American Bar Association (ABA) has backed the use of DNA evidence in forensic science, but delivered a very cautioned warning. Lawyers have been urged by the ABA not to oversell DNA evidence to juries. Telling a jury that no one else besides the defendant can have the same DNA is rarely justified. Complications arise when one considers that many people have likely passed through that area both before and after the crime, depositing their DNA and contaminating the scene. Through a process known as secondary transfer, DNA can arrive at a scene after being transferred on another person’s body or clothing.
The takeaway is that many people and jurors have unrealistic perceptions about the evidentiary value of DNA evidence, and this can often result in miscarriages of justice. It should always be considered in context with all other available evidence.
Philadelphia Civil Rights Lawyers at Williams Cedar Help Victims of Wrongful Conviction
When wrongful convictions happen, victims and their families usually suffer from long-term emotional and economic problems. The Philadelphia civil rights lawyers at Williams Cedar advocate for victims of the justice system. To schedule a consultation at one of our offices in Philadelphia or New Jersey, call us today at 215-557-0099 or 856-470-9777 or contact us online.