Assault and Battery are known as crimes against persons as they involve either the threat of violence (Assault) or the actual physical touching or infliction of injury (Battery).  Assault has varying degrees from 3rd degree (the least severe) to 1st Degree Assault (the most severe). 

1st Degree Assault  -- Class A or B Felony
2nd Degree Assault -- Class B or C Felony
3rd Degree Assault --  Misdemeanor

Common defenses to Assault Charges:

The most common defense is either the defendant did not actually assaulted the claimed victim or that the assault was justified as self defense. Many factors go into these defenses, such as comparable size and strength of the victim and the defendant and what was the basis for the self defense since self defense does not allow the defendant to escalate the level of violence.  In example, in most situations, being pushed does not justify shooting someone in self defense. The trickier situation is when the levels of violence are closer together, such as responding to a push with a punch, that can be argued as justifiable self defense and will ultimately need to be decided by a jury if the facts justified the escalation of violence.     

Provocation.  While provocation does not exclude criminal responsibility it is relevant on the issue of culpable mental state in assault cases. Similarly, sudden passion arising from adequate cause affects the gradation of assault charges. Provocation involves more than insults, the Missouri Supreme Court has commented that “little more” than words is required, it generally has been held that provocation must be sufficient to arouse such passion as to render a person of ordinary temperament incapable of reflection, or to obscure reason. Usually, there must be some actual or threatened force or violence to the person to constitute provocation amounting to adequate cause for sudden passion