Could it be possible that JonBenet's scream was interupted by a whack on the head or more likely a stun to the face? Then could the jerk have tried to quickly escape through the window. With the black mark on the wall under the basement window, he could have tried to climb out but was unable to make it all the way. Looking at the direction of that mark, it seems more likely to me that it could have been made by a toe of a shoe and not a heel. A frightened leap at that window could result in the grate being pushed open part way up, then dropped making the noise, trapping the green plant material beneath it, and causing the disturbance of debris at the window. Has anyone tried to climb out of that window? If he couldn't get out by himself that would also account for the suitcase being put there. Just some thoughts, errors and omissions expected.