Oswald fired his first shot through this tree, stripping the brass case off the slug and sending a shower of brass fragments sparking on the asphalt behind Kennedy's limo. The slug refracted off a tree branch and struck the curb on the far side of the plaza, sending a concrete chip up in the face of an onlooder, drawing a few drops of blood. He had made the same mistake earlier when he tried to shoot General Edwin Walker through a window in his Dallas home. Oswald didn't realize that you can't shoot through things, that it changes the trajectory of the bullet.