What documents can show that I was in unlawful status as of June 15 2012?

If you are referring to the Deferred Action for Childhood Arrivals program, you only have to prove you were in the US on June 15, 2012 (and that you were 15 years old or older on that date), which could be done with a number of documents depending on your situation.  You don't need an I-94 card to prove this point.  The passport would not prove when you were in the US at any given time, it would only prove the date that you entered.  You should work with a lawyer to help you build the best evidentiary case you can.  I would, of course, be happy to help you for a fee, but any immigration lawyer can help you establish the proof needed to qualify to this program.