Who decides if someone is qualified as an expert witness?

The person that decides if someone qualifies as an expert witness is the judge. However, there are very minimal requirements for someone to have this title of an “expert witness” in court. The person attempting to qualify as such simply needs to have knowledge, skill, experience, or training (or some combination of all of the factors) that make it difficult to find someone else that has as much knowledge about whatever the case is about.

If someone has a few hundred hours of experience, and has worked on cases in a variety of places, it’s usually a pretty safe bet that they’ll be qualified. However, the judge will have the final say on what counts. This can vary from state to state, since the federal requirements are so minimal.