A sociologist who holds a doctorate degree in her field claims to have studied 150 cases involving f

A sociologist with a doctorate degree in their field and having the knowledge, skill, experience, and training, as well as the opportunity to have studied 150 cases involving false confessions and opines, should be able to testify and have her opinion heard by the jury. In accordance with Federal Rule of Evidence 702, as long as the sociologist meets all the requirements she should be able to testify in the form of an opinion in court. As explained in our book, “Expert testimony may be admissible when the subject matter at issue involves concepts with which the average person is not sufficient familiar, but will generally be excluded where such testimony would add little information for the jury.” (Ingram 459)

The quick answer is "it depends."  It depends on the jurisdiction, the court, the attorneys, and the individual judge. Each state may be different in it's opinion to allow along with levels of the court, ie. federal, state, county, etc.

It's my understanding in basic court procedure that both attorneys would have to agree on classifying this person as an expert witness and allow her testimony in this particular trial. She would be questioned by both defense and prosecution in open court to verify her credentials and expertise. The judge would then make the ultimate ruling to allow or disallow.

Explanation:

This type of example would also apply to cases in which an expert in the field of use of force would testify to a deadly force incident and to give a recommendation on whether a lethal use of force was justified or not justified based on their expertise and credibility.