<P> Ultimately , the person who pulled the trigger was revealed to be Kristin Shepard ( Mary Crosby ) in the `` Who Done It ? '' episode which aired on November 21 , 1980 . Kristin was J.R. 's scheming sister - in - law and mistress , who shot him in a fit of anger . J.R. did not press charges , as Kristin claimed she was pregnant with his child as a result of their affair . </P>
<P> Ultimately , the person who pulled the trigger was revealed to be Kristin Shepard ( Mary Crosby ) in the `` Who Done It ? '' episode which aired on November 21 , 1980 . Kristin was J.R. 's scheming sister - in - law and mistress , who shot him in a fit of anger . J.R. did not press charges , as Kristin claimed she was pregnant with his child as a result of their affair . </P>
who shot jr on the tv show dallas
who shot jr on the tv show dallas
Kristin Shepard ( Mary Crosby )
Kristin Shepard ( Mary Crosby )