This is a common question with a complicated answer.
Some people do make changes in their actions and the beliefs that underlie the violence.
Such change takes a long period of time. And some people may not change, even if they attend a batterer intervention program. In fact, thousands of people attend this program, often against their will. For example, everyone convicted of a domestic violence offense in California is required to attend a 52-week batterer intervention program. These programs should not be called treatment because people who batter are not sick or ill but must change their belief system that justifies violence in their relationships.