Competitive and brash by nature, MacArthur plays the "bad cop" of the simplistic duo. She is not above abusing her power by breaking a few rules in order to win. She is known for being an aggressive person, as well as being a control freak; when she wants to get something done, she will complete it whatever the cause may be. This ranges from commandeering a taxi from its driver, to giving a ticket to Sanders for "excessive complaining" and passing gas right in front of her partner. MacArthur is proud of her physical skills and often teases her partner for being weaker than her. Despite this, MacArthur is not without a code of honor as she is still willing to uphold the law.