Rule 701 Opinion Testimony by Lay Witnesses

When a regular witness testifies in court, they normally can only talk about what they actually saw, heard, or experienced. They can't just give random opinions about things. But there's an exception that lets them share opinions in certain situations.

A witness's opinion is only allowed if it meets three requirements. First, the opinion has to come from something the witness personally noticed or experienced, not a guess or assumption. Second, the opinion has to actually help the court understand the witness's testimony better or help figure out an important fact in the case. Third, the opinion can't be based on special training, science, or technical knowledge. That kind of opinion can only come from an expert witness who has been qualified to testify about those specific topics.

This rule matters because it draws a line between what everyday witnesses can say and what experts can say. For example, a regular witness could say someone "seemed drunk" if they saw the person stumbling and smelled alcohol, because that's based on what they observed. But that same witness couldn't testify about someone's blood alcohol level or explain how alcohol affects the brain, because that requires specialized scientific knowledge that only an expert can provide.