 At which point the audience burst into laughter. That was Booth's cue. He entered the inner box, approached the President rapidly from behind, reached into his pocket, pulled out a .44 caliber Derringer, and fired once into the back of the President's head. The first man to realize what had happened was Major Rathbone. He had been sitting in the corner. He jumped up and struggled with Booth. Booth threw the gun down, pulled out a dagger, and tried to stab Rathbone in the heart. Rathbone defended himself, but he was sliced to the bone.