After John Wilkes Booth shot Lincoln, Leale rushed to Lincoln's box where he briefly examined Henry Rathbone, whom Booth had stabbed in the arm. He then saw Lincoln slumped in his armchair supported by Mary Todd Lincoln; Lincoln was unresponsive, barely breathing with no detectable pulse. Initially thinking Lincoln had been stabbed, he laid him on the floor and, with bystander William Kent, cut off Lincoln's collar and opened his coat and shirt in search of wounds. After realizing that Lincoln's eyes were dilated, Leale found the bullet wound at the back of the head. Leale was unable to locate the bullet, which was deep in Lincoln's head, but after he dislodged a blood clot Lincoln's breathing improved; he found that regular removal of clots maintained Lincoln's breathing. He also gave artificial respiration. His assessment, however, was that Lincoln could not recover. By this time other surgeons from the audience had arrived, including Laura Keene, who cradled Lincoln’s head, while Leale announced that Lincoln wasn’t going to survive.