Who is John Anderton? How does he react to Ed Witwer’s presence?

John Anderton is the leading cop in the PreCrime division, a law enforcement unit charged with stopping future murders that have been pre-visualized using special technology. He is the protagonist of the film, and his journey through the film shows the fine line between right and wrong. Initially he is on the side of “right,” catching criminals and saving the day, but soon he becomes a fugitive wanted for the (future) murder of Leo Crow—a man Anderton has never seen nor heard of. The PreCrime unit is being audited for its effectiveness and efficiency by Danny Witwer of the Department of Justice. Anderton takes exception to this.