The Shootout in Imperial Palace Hotel is one of the events in the Organ Harvesting case where Da Silva asks Max to investigate a place where suspected to be where all the people kidnapped move to.
The event resulted in the complete destruction of not only the Imperial Palace Hotel, also the Cracha Preto.
Da Silva drops Max off near the Imperial Palace Hotel, The Cracha Preto's hideout and front building. Once in the hotel, Max finds a group of kidnapped civilians in a room, and releases them from their captivity. One of the people he releases is Serrano, now a beaten and "pathetic" man.
Max fights his way through the hotel until he finds a morgue inside the building, where he confronts Arthur Fischer, a doctor and one of the men behind the body harvesting. Fischer begs for his life and offers money to Max. Serrano soon interferes and confronts the doctor for his crimes, ultimately killing him as Max leaves the scene.
The event resulted with the destruction of the Cracha Preto's HQ, Imperial Palace Hotel, the death of the Cracha Preto leader, Alvaro Neves and the dissolution of the Cracha Preto. Max Payne and Raul Passos managed to escape with enough evidence linking the Cracha Preto with the UFE and Victor's involvement with the organ harvesting. This lead to Max attacking the UFE station to confront Becker, one of the key player in the organ harvesting scandal.