Rule 90.901 Requirement of authentication or identification

Before you can use a piece of evidence in court, you have to show the judge that the evidence is what you say it is. For example, if you want to submit a text message, you need to prove it actually came from the person you claim sent it.

You do not need to prove this beyond all doubt. You just need to show enough proof that a reasonable person could agree the evidence is genuine. Once you clear that bar, the judge will allow it in.