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who shot dexter's sister in season 4
Christine Hill has been following her father around to try to clean up after his killings, and shot Lundy and Debra when they got too close to Trinity's next target.
who shot J.R. on dallas
The November 21 episode solved the mystery, identifying Kristin Shepard, J.R.’s wife’s sister and his former mistress, as the culprit.

Question: who shot mr. burns
Self-contained rewrite: who shot mr. burns on the simpsons