Thatch is a curator at the Gotham Museum Of Art.
Meeting with the GCPD
After Edward Nygma robbed the Museum, he meets Jim Gordon and Harvey Bullock and tells them about Mad Grey Dawn the first painting defaced by Nygma he then helps them by showing them the other paintings, that Ed defaced.
Jim asks about why the robber would put green question marks over the signatures, Thatch tells them that there are entire books written on them, but Jim says he wants to keep it simple. Jim asks about their names they work out that the names make 'Market' 'Street', Jim ask about the painting they stole and Thatch explains it was based on a bombing known as 'Bloody Monday' Jim says "Today is Monday" before heading to the Union Station on Market Street.