Crook, the President’s chief bodyguard, was off-duty. In his place, John F. Parker was responsible for the President’s safety. Accounts vary on Parker’s whereabouts at the precise moment Booth entered the 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 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 a 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, about ten minutes ahead of fellow conspirator David E. Herold, as he fled to Anacostia. (You will need Adobe PDF for this link.) The police blotter reveals Booth was the suspect police would try to find.