Moderators can view a history of all the comments left by a user, including deleted ones (profile → mod → info → comments). This is convenient, among others, when investigating situations involving two users such as potential harassment or suspected sockpuppets.
For these cases, it would be more helpful if the view listed the target of each comment. The target is currently indicated only for comments with an @mention. Comments intended for the post author do not carry any visible indication of who the author is.
Even better would be to add a way to filter this view to see just comments from X to Y.