Accounts vary on Parker’s whereabouts at the precise moment Booth entered the State Box. Some say the President permitted him to take a better seat, thereby leaving Lincoln unguarded. Others say he was in a tavern across the street and wasn’t seen again until around 6 a.m. the next morning.
With no one around to stop him, Booth pulled out his pistol and fired one shot into the President’s head. The bullet (which was later removed in an autopsy) entered through his left ear and lodged behind his right eye.
As the President slumped forward, perhaps grasping one of the flags draped in front of him, Major Rathbone struggled with Booth who, using his knife, slashed Rathbone’s arm.
Booth jumped from the box, but the spur of his boot caught (and tore) a U.S. Treasury Guards flag. When he fell to the floor, he fractured his leg. It is said that Laura Keene rushed to the President's box with a pitcher of water. As the actress helped to care for the stricken President, his blood allegedly stained her cuff.
Undaunted, Booth fled the theater through the back door and escaped on horseback. He crossed the "Eastern Branch" of the river, on the Navy Yard Bridge, about ten minutes ahead of fellow conspirator David E. Herold.
With Washington, D.C. behind him, Booth was a wanted man. About 1,000 people were in Ford's Theater when he shot the President. The police blotter shows he was the only suspect police would try to find.