on the street , directly in front of the house , there was a ford county sheriff 's patrol car , and behind the wheel sat one louis tuck , a full-time deputy who worked the graveyard shift and whose primary responsibility was to be seen in the neighborhood throughout the night and , specifically , to be parked near the mailbox at precisely 5:45 each morning , monday through saturday , when mr. brigance stepped onto the porch and waved hello .