While the criminal justice system has often been reluctant to treat the husband who batters as a criminal, there is no similar reluctance when the battered wife responds to continued abuse by killing the abuser. Expert testimony on battered woman's syndrome can, at the very least, clarify for the judge and jury the reality of the prolonged and severe abuse the battered woman has suffered and its effects. Expert testimony on battered woman's syndrome is extremely important in combatting the misconception that wife abuse is a family squabble, not a crime; and that when the woman uses deadly force against the abuser, the reasonableness of actions is suspect. Expert testimony can be useful in supporting a claim of self-defense by enabling the jury to understand how abuse affects the battered woman's perception of danger, especially when she reacts to a less than overt threat of harm. It can be particularly useful in support of a duress defense, because the woman who suffers battered woman syndrome is constantly coerced through violence to act according to the will of her batterer to survive. Expert testimony and education within the criminal justice system are of paramount importance in convincing law enforcement and the courts of the reality of the danger faced by the battered woman and in ensuring that battering is treated, not as a family affair, but as the crime it is. 230 footnotes.