Can somebody use text messages between two parties that were read from a different device as evidence with out either of said parties being ...

Question

Can somebody use text messages between two parties that were read from a different device as evidence with out either of said parties being aware of it? Example: I texted my sister iPhone to iPhone. Soon to be x-husband reads text messages from her iPad he took when he left, (which by the way was an anniversary gift he refuses to return.) Can he use those texts as evidence to incriminate her? Any legal advice in this matter is greatly appreciated.

Answer

Question: How does anybody know who sent the text messages? Did anybody SEE the person who sent them? This ends up being a problem of authentication/hearsay.

In other words, I can't come into Court and testify, "Judge, this is a text message that Jack Adams sent to me." I don't know who sent it. I didn't see who sent it. I may THINK I know who sent it, but I can't TESTIFY as to who sent it.