A recent overturning of a innocent’s man’s conviction is another example of how experts can be dangerous to a criminal trial. Experts are usually needed to provide specialized information that would not be in the jury or judge’s area of knowledge. An expert’s job is to help the trier of fact, understand parts of the evidence and ultimately whether the defendant is guilty or acquitted of the charges faced.

Sometimes, the expert’s opinion goes too far, and their findings block out any other testimony that contradicts this. When faced with this outcome, defendants often plead to lesser charges afraid that a definite conviction would result for the more serious charges. This is what happened in Mr. Blackett’s case. Fortunately, the system worked to overturn his conviction, but unfortunately, after he served his sentence. Experts can be useful but their findings should be independently tested.

https://www.thestar.com/news/investigations/2018/10/02/what-happened-to-oneil-blackett-is-a-tragedy-judge-says-in-wrongful-conviction-case.html