It can be hard to grasp the extent of domestic violence. The latest Bureau of Justice Statistics report estimated that domestic violence accounted for 21% of all violent crime in the U.S. from 2003–12.
You can read more about it at: http://www.bjs.gov/index.cfm?ty=pbdetail&iid=4984
But how can the prevalence of domestic violence be lessened? The Police Foundation has continued to fund research to answer this question since the Minneapolis experiment described in chapter. You can read about some of the latest research (and about the earlier studies) at: http://www.policefoundation.org/content/domestic-violence-victims.