Defense against 1st degree impersonation?

for a school project, we are supposed to play the defense for a case against 1st degree criminal impersonation. In the movie Gattaca, Vincent Anton Freeman impersonates Jerome with consent. He even supplies him his blood, hair, skin cells and many more, so that he can achieve his dream, and pass drug test. But people find out that Vincent is playing Jerome, but they allow him to still pass the test. We need some help. Thanks!