Tis merely Reinholdt. Based off of that bloody fist and bloody shoe and the blood on the wall, someone's been pitching a fit. A second look would show that Reinholdt himself seems relatively unharmed, if obviously exhausted and frustrated. Silly unnatural healing.
The screen is paused on an image of Chelonie in the rose garden with Dani and a brown cat with a blue star if I remember it all correctly. Chelonie is pointing the gun at the cat.