As far as we know, in the previous games of the series after the disappearance of corpses remain in their place the contours drawn in chalk. In SA from the chips declined, but this script makes her return to the game.
The contours are two variations can appear near five corpses simultaneously but do not appear when the player stands near the open-air savegames. The script works even during missions.
Contours disappear after some time, or when a player far would be breaking away.