Then shouldn't you look at whether the act violence involves two people of criminal background instead of looking at their gender?
Just because someone is subjected to violence from someone who shares some group characteristics doesn't mean it's not worth investigating or that he or she is somehow responsible for this violence.
A similar logic could be applied to black men on black men violence, to cite other answer that you got.
To push it further I what stops us from using the same reasoning to say that it's not worth investigating domestic violence in the case of same-race couple? In the end it's just whites hurting whites.
Just because someone is subjected to violence from someone who shares some group characteristics doesn't mean it's not worth investigating or that he or she is somehow responsible for this violence.
A similar logic could be applied to black men on black men violence, to cite other answer that you got.
To push it further I what stops us from using the same reasoning to say that it's not worth investigating domestic violence in the case of same-race couple? In the end it's just whites hurting whites.