Name the actor who killed the wife of William Wallace Braveheart believed to be playing Sir William Heselrig.?

The actor who played Sir William Heselrig in "Braveheart" is David O'Hara. In the film, Heselrig is depicted as the character responsible for the death of William Wallace's wife, Murron. O'Hara's portrayal contributes to the film's dramatic narrative surrounding Wallace's quest for revenge and freedom.