If dss calls me about my brother do I have to call them back

No.

What about in mass because I thought I didn't have to but I'm not to sure

It for my girlfriend her and her brother got in a fight and he beat the crap out of her and a friend call dss on her brother and now they keep calling wanting her side of the story but she just want them all to leave her alone and her brother wants her tolie

it for my gf her and her brother got in a fight and he beat the crap out of her and a friend call dss on her brother and now they keep calling wanting her side of the story but she just want them all to leave her alone and her brother wants her tolie

Ok. I hoped that simply saying "no" I would get you to give me enough information to work with. :D

They can't somehow punish you for failing to return a phone call. And I doubt that, even if they knock on your door in person, they can force you to answer their questions. That can only be done by a court order.

You are not required to talk to them, they may even try and fake you out by coming to your door with someone that has a badge, police, sheriff office, and so on, but unless they have a warrant to enter your home, you don't have to let them in, and personally I would never let them in my home unless they had one.

They can issue you a court order to come into the court but again, they can not force you to make a statement or answer questions.