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Reasonable Degree of Medical Certainty in Expert Witness Testimony

Medical certainty affects what possible surgical procedure, treatment or medication a person would receive for a condition the patient possesses that could harm him or her. However, these words do not necessarily define a standard or require certain reference materials for the medical expert within his or her field of study.

Expert testimony provides the necessary opinion or certain facts with a degree of reasonable medical or scientific certainty regarding the subject matter. Within the reasonable degree of certainty in the field of study may change depending on the elements of the subject or the circumstances of the case. However, these words are generally not used when the expert is not in the courtroom. This may lead to the terminology meaning something different in varying situations. The words have no defined meaning in standard medical reference books, materials or studies. The meaning behind the words appears to only have a true relevance in a courtroom for testimony to remain admissible.

The Words Confusing or Misleading

When a person uses the words to a degree of medical certainty, they often confuse someone attempting to find the facts of the case and pursue
the truth. The National Commission on Forensic Science or the NCFS stated that the scientific community should not use these words as part of terminology. It is also important to note that the legal community should not promote or recognize these words with medical professionals when not in the courtroom. There exists no scientific foundational basis for the use of these words when the person is not in a courtroom for a case.

What the Words Mean

The expert tasked with a case needs to put his or her experience and knowledge to work in determining if evidence connects the defendant to the actions. In a medical case, this may mean that the professional knows through his or her working understanding of methods, practices and education that a diagnosis or treatment is necessary or will improve the chances of the health of the patient. To his or her knowledge of the issue or incident, he or she has a reasonable degree of certainty in medical terms that the diagnosis is certain or that the treatment will help the person.

The words have a greater meaning in the courtroom context even if the professional or lawyer would never use the words outside of the courts. By having a greater degree of certainty, the person may increase chances of admissible forensic or medical evidence. The use of the words provides a context to the evidence, treatment, diagnosis and medical knowledge or understanding of the medical matter to the judge or jury. This may increase the awareness of the courtroom or provide better clarity or confidence in the evidence or expert. The words may place more faith in what the professional may say next with his or her testimony.

The Meaning of Expert Witness Testimony

Through the necessary use of the words in the courtroom, they have a direct connection to the expert witness’ testimony. A reasonable degree of certainty translates to the expert expressing his or her opinion that the information provided for the case is sufficiently reliable based on a low margin for error. The standard five percent error in testing methods is the usual found to ensure the best results. Any higher than this and the professional may have unreliable outcomes to testing evidence or other materials. Admissibility in evidence requires the lowest degree of error. This then gives the expert a higher degree of certainty that his or her opinion has a foundation in what he or she believes to remain the truth in the case.

For forensic science and scientific methods applied to evidence and materials, the expert may express a reasonable degree of that he or she used his or her best judgment to apply processes and outcomes to the case. Then, he or she may explain the issue without little doubt that there is an alternative. It is crucial the expert remains consistent in his or her testimony as a lower percent of error may relate to the evidence or circumstances of the case.

The Expert in Reasonable Certainty

While the expert may understand that a reasonable certainty is only for the courtroom, he or she may present his or her findings to the judge or jury as reasonably sound. This will provide more confidence in testing methods and evidence when the words have a necessary use.

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Disclaimer: While every effort has been made to ensure the accuracy of this publication, it is not intended to provide legal advice as individual situations will differ and should be discussed with an expert and/or lawyer.

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