My very unprofessional advice is:
1. Recognise the person is in a vulnerable situation.
2. Offer comfort and support...listen.
3. Recommend social service agencies, DV shelters and DV counselors.
4. Give CONTROL to the abused person.
5. Allow them to decide what they will do.
6. DO NOT attempt to tell the person what to do.
7. DO NOT defend or make excuses for an abuser.
If anyone reading this is a professional.........offer comments, corrections or suggestions please.