Bram Voss's Alibi

I asked Bram Voss where he was last night, says Mardler as the two of you walk past a lush ficus into his office. He told me he was out on the water on his boat. Then he went home to his wife, but I think he was hiding something, not much of an alibi. None of the stuff that we can see helps his alibi that he was on a boat. We're going to pressure him with a fact. What's the fact that we're going to Pressure him?