The Role of Expert Witnesses in Criminal Cases

An expert witness brings specialized knowledge and the ability to provide their opinion, which can help tip the scales in your favor in a criminal case. But what is an expert witness? How are expert witnesses different from other witnesses? And do you need an expert witness in your criminal case?

Stephen Lebedevitch is a criminal defense attorney in Fairfield, Connecticut, who represents people charged with crimes throughout the state. He has over a decade of experience representing people charged with crimes and can evaluate your situation, offer advice and legal guidance, and defend you in court. Here, he describes the role of an expert witness in criminal cases, identifies the types of experts commonly used in criminal cases, and explains how to decide whether your case will benefit from expert witness testimony.

If you were charged with a crime in Connecticut, contact The Lebedevitch Law Firm, LLC, today to speak to an experienced criminal attorney.

What Is an Expert Witness?

An expert witness is someone with specialized skills, knowledge, training, or experience relevant to a particular legal situation. Because of their specialized knowledge, an expert witness may be called upon to interpret evidence or explain technical matters that are beyond the knowledge of a layperson. Unlike lay witnesses, who are not allowed to offer an opinion in a court case, an expert witness can express their opinion on many matters at issue in a criminal case.

Who Can Testify as an Expert Witness?

Expert witnesses can come from almost any industry or profession. An expert witness could be a doctor, an engineer, a financial analyst, or even a high school teacher. The key factor is that they possess specialized knowledge, skill, training, or experience that can help the jury understand complex, technical evidence that is a factor in the legal matter in question.

What Types of Experts Are Commonly Used in Criminal Cases?

Expert witnesses that are commonly called to testify in criminal cases include:

• Medical experts. Doctors, nurses, and other healthcare professionals may be called upon to interpret medical records, determine the cause of death, describe their findings after analyzing a medical sample, describe a person’s mental state, or explain how a person’s body metabolizes drugs or alcohol.
• Forensic experts. A forensic expert may be called upon to analyze a crime scene, interpret forensic evidence like DNA, fingerprint, or ballistic information, interpret and explain drug test results, or analyze physical evidence like shoe prints, tire tracks, or whether a particular tool was used to commit a crime.
• Financial experts. Accountants, economists, and other financial experts can interpret, analyze, and provide insight into economic losses, business valuation, the location of certain assets, and other complex financial situations.
• Mental health experts. Psychologists, psychiatrists, and other mental health professionals can analyze and assess a person’s mental state, provide insight into a person’s mental state, capacity and competency, opine whether a defendant was legally sane when a crime was alleged to have occurred, provide a mental health diagnosis, or explain the effect of trauma, abuse, or PTSD.
• Engineering experts. Engineering professionals can analyze and testify about technical and mechanical aspects of a criminal case, such as accident reconstruction, the cause of a fire or explosion, and whether systems or structures were functioning properly or were up to code.
• Digital technology experts. IT professionals and cybersecurity experts can analyze and interpret digital evidence, recover hidden or deleted files, analyze internet browsing history, authenticate text messages, social medical posts, and other digital communications, investigate allegations of hacking or unauthorized access, opine whether the chain of custody was preserved, and help determine whether a suspect or device was linked to an alleged crime.

What Is the Role of Expert Witnesses in a Criminal Case, and How Do They Help?

Experts are often tasked with presenting complex technical evidence in a way that is accurate and accessible to a lay audience. For example, an expert witness may be asked to educate the jury on a complex or highly technical subject. An attorney may call an expert to challenge someone else’s interpretation of the evidence, provide an objective analysis of a particular set of facts, or help a jury understand the trustworthiness or applicability of a witness’s testimony. An expert witness could also be asked to analyze and interpret the facts of a case, provide an opinion on the conclusions they drew from certain evidence, and explain their findings to a jury.

The right expert can play a pivotal role in a criminal case, and the power of an expert witness to influence the jury’s perception of a case cannot be overstated. Jurors often look to expert witnesses for guidance in interpreting complex evidence. The expert’s demeanor and testimony can profoundly affect the jurors’ perception and, ultimately, the outcome of the case.

By presenting alternate explanations and challenging the prosecution’s claims, an expert can offer new theories for the jury to consider, shifting the burden of proof back to the prosecution and forcing them to justify their assertions.

How to Choose the Right Expert Witness in Your Criminal Case

Choosing the right expert witness in your criminal case is crucial. An experienced criminal attorney can identify the type of expert or experts you need, evaluate their qualifications and credentials, ensure they meet applicable evidentiary requirements to qualify as an expert, and ensure their opinions fit with your overall defense strategy.

Contact The Lebedevitch Law Firm Today

Stephen Lebedevitch is a veteran trial attorney who represents people in Fairfield and New Haven counties and throughout Connecticut. Contact our law office today to schedule an appointment to discuss your situation and how we can help.