Missouri Predominant/Dominant Aggressor

455.085.  Arrest for violation of order — penalties — good faith immunity for law enforcement officials.

  1. When an officer makes an arrest, the officer is not required to arrest two parties involved in an assault when both parties claim to have been assaulted. The arresting officer shall attempt to identify and shall arrest the party the officer believes is the primary physical aggressor. The term “primary physical aggressor”is defined as the most significant, rather than the first, aggressor. The law enforcement officer shall consider any or all of the following in determining the primary physical aggressor:

(1) The intent of the law to protect victims from continuing domestic violence;

(2) The comparative extent of injuries inflicted or serious threats creating fear of physical injury;

(3) The history of domestic violence between the persons involved.