Can you trap him? one of those stuffed animals with a tape recorder or a video camera inside? Tell your daughter to keep it with her at all times? careful. What jurisdiction do you live in? Laws and understanding of abuse vary from location to location. Support services do as well. Are you in a support group? If you identify your ex as an alcoholic or addict you can attend Al-Anon at the least, they might know the local system better. When my mother felt she could not escape my fathers control of us, I wish she had fled the country if she could come up with nothing else.
If you fear being unable to return because of custody, when the kids are 18 they are free.
Prison is another matter :(
Have you sought help from a local religious institution?
If he has records of DV against you, why is he not in prison? something is very wrong. In tampa, FL, if a man even comes close to physically abusing his family, he can receive a "no contact" order. You live in a very, very backwards place. Are you only talking to local people? Can you approach state, or even federal sources?
p.s. Your daughter has a therapist, how about MD? psychiatrist? legally they have more sway