Complex sentence: Keller isn't convinced that' Brenner'is all that he says he is and manages to find proof of the deception, showing Kaminsky's photo to a police informant who arrested the real Brenner in the past.
Split into simpler sentences: Keller isn't convinced that' Brenner'is all that he says he is. Keller eventually manages to find proof of the deception, showing Kaminsky's photo to a police informant who arrested the real Brenner in the past.