R. Kelly is due back in court Friday for the latest in a series of hearings in advance of his trial in Chicago. It’s been two years since the singer was indicted on charges of child pornography, and to make their case, prosecutors are going to have to prove three crucial things:

-That the infamous sex tape that emerged more than two years ago is authentic,
-That the man on the tape is indeed R. Kelly, and
-That the girl on the tape is underage.

But how can they prove that, when Kelly insists that the man in the video is not him, and the girl in question insists that the girl in the video is not her — even though 50 people acquainted with her claim that it is?

Prosecutors hope to overcome these claims with facial and body comparisons. They also have more tools to use — and more obstacles to overcome than merely trying to prove the identities of the people on the tape.

Credit: MTV News