Expert witnesses are respected members of their profession who are trusted to provide truthful accounts in court, however if their credentials are found to be inaccurate or misleading, their testimony may be deemed unreliable. One recent example underscores the importance of verifying expert witnesses' credentials for your own and opposing legal teams. Earlier this year, NASCAR driver Jeremy Mayfield's key expert witness was found to have inaccurate credentials, weakening his defense such that his drug suspension will be upheld until his trial in September 2010. According to ESPN, Mayfield's attorneys planned to use Harvey MacFenerstein's statement that NASCAR used flawed drug testing procedures to dispute Mayfield's suspension following a positive drug test. However, NASCAR attorneys found inaccurate information about MacFenerstein's education in his affidavit and used it to invalidate his authoritative opinion. MacFenerstein, the president of a toxicology company, claims that he told Mayfield's attorneys to change this information before submitting his opinion in late May. Regardless of how or why the incorrect information was submitted, MacFenerstein's argument and reputation came to question and his testimony could no longer be used in Mayfield's case. Mayfield's attorneys were relying on MacFenerstein's testimony as a pivotal component of their case, so discrediting him was a major victory for the prosecution.
To learn more about choosing powerful expert witnesses, read our previous blog entry.