The Role of DNA Evidence and Its Influence on Criminal Defense Cases: Pros & Cons

Whenever you are fighting a battle in modern courtrooms, you know that DNA evidence has become one of the most powerful weapons in the field of criminal justice. But while it is considered some of the most powerful evidence, it’s crucial to understand that it has both negative and positive sides. It has its strengths and limitations, particularly when it comes to defending the accused in the court.
As a criminal defense attorney, it is crucial to understand how DNA can help or undermine a case. At The Ambeau Law Firm, we know how to examine this forensic evidence, meet the challenge by focusing on the limitations, and use it to defend your legal rights. The pros and cons of the DNA evidence are stated below, how it works, and what are the things every defendant should know. 

What is DNA evidence?

DNA evidence stands for the genetic material collected at any crime scene or from any person involved. Biological substances that contain DNA, such as blood, skin cells, or saliva; recovered from people or surfaces in the crime scene. DNA plays a pivotal role in possibly identifying the perpetrator who committed the offense. Because each person’s DNA is unique, with the exception of identical twins, and the science is capable of resolving an unknown profile collected, this evidence has the power to resolve the mystery of “who done it”. In criminal cases, this evidence has a significant impact on prosecutions, from jury trials to exonerations. 

How is DNA evidence collected?

DNA evidence is collected by forensic experts from key areas at a crime scene. Common sources include weapons, the victim’s body, under the fingernails during a struggle, and items a person may have touched—like cups, door handles, or clothing. Proper collection and handling are critical because DNA plays a major role in building a strong criminal defense case. At Ambeau Law, we closely examine how DNA was collected to ensure your rights are fully protected.

Pros of DNA evidence in Criminal Defense

DNA can be the most pivotal asset to any criminal defense lawyer, if it is used correctly.

1. Can liberate the innocent
   DNA has helped prove hundreds of people innocent who were wrongly accused and unfairly convicted. It can exclude a suspect from being connected to a crime scene by showing that the DNA present is not related to the accused.
2. High level of accuracy
   If DNA samples are handled properly, they will provide crucial analytical information. In fact, concordant profiles are often presented with the “match” possibilities in the quintillions and beyond.
3. Can challenge weak evidence
   DNA could deliver a clearer picture if other evidence (such as eyewitness testimony) is unreliable. It gives defense attorneys a scientific foundation to challenge the circumstantial evidence.

Cons of DNA Evidence in Criminal Defense

DNA is not always straightforward and clear-cut; only a criminal justice attorney skilled in forensic science, or educated as we are at Ambeau Law, will understand the limitations and work accordingly. 

1. Risk of contamination
   It is easier to contaminate DNA when it is being collected, stored, or tested. Additionally, DNA can be deposited without contact and by innocent persons otherwise in the crime space. Investigators may be deceived by innocent deposit or transfer.
2. Partial and mixed samples
   DNA that is discovered is often not complete or mixed with other profiles. With the current kits, full DNA profiles can be developed with as little as a few cells. To deal with this, this kind of evidence requires an expert’s analysis.
3. Abuse and Misunderstanding
   Juniors can overestimate the accuracy and specificity of DNA because of shows like CSI. Without a proper explanation, the DNA evidence can be misleading and used to convict an innocent person.

Activity-Level Assertions

As stated earlier, DNA evidence is collected by forensic experts from key areas at a crime scene. There is no scientific support for an expert telling the jury the manner in which DNA was deposited on a surface, not even if the DNA profile is developed from a blood stain. As we talk and breath, DNA is expelled into the air, and that DNA can fall on any surface. DNA can be transferred one or two or more times, from a person to a surface, where the DNA on the surface is from a person that never came in contact with the surface. Because this is the case, the expert cannot say how the DNA was deposited.

This occurs often in gun cases and sex crimes cases where DNA is found on a gun or person and the Expert from the prosecution tries to say that the accused touched the gun or person. The science does not support this kind of activity assertion. There is no way to know how the DNA got on a surface and a statement of that kind should be inadmissible.

The Role of A Criminal Defense Attorney in DNA Cases

DNA evidence can only be beneficial when your defense attorney can analyze, challenge, and present it intelligentlyR

• Examine the chain of custody by crime scene personel.
• Examine the lab procedures and protocols.
• Have an expert level understanding of the forensic science evidence.
• Challenge the offer of the evidence and make sure it is being measured properly

Our firm’s lead lawyer, Jarrett P. Ambeau, has a wealth of knowledge in both sophisticated criminal defense and scientific evidence. He is a court-qualified DNA Interpretation expert. We understand how to meet the challenge of complex DNA evidence and use it to your advantage rather than against you.

DNA evidence can either make or break the case. It’s a powerful support, but it’s not perfect. That’s why anyone facing serious criminal charges should work and rely on a strong criminal defense attorney who understands both science and the agenda of courtrooms.

If you and someone you love is facing serious, unfair charges against them where DNA is involved, don’t wait, contact The Ambeau Law Firm today for guidance and consultations. We will protect your rights, challenge the unreliable evidence, and fight for justice boldly.