Because by that logic, he never has to stop; he can continue to harass her until
he finally accomplishes his objective (grounds to arrest her)- in which case, why bother with the pretense?
There's Deathmatch (yes, like always, it's all about the killing), Infiltration (which has you going against the opposition to
accomplish objectives before them, earning you points towards the victory), Capture the Greased - up Deaf Guy (Capture the Flag with a twist, of which has you chasing around a naked and greasy man to get hold of the flag), and
finally Multiverse Madness (a Horde like mode, which sees you teaming up to take on waves of AI opponents from the different universes in the game).