My Sisters Fil Is Violent And Has Threatened Her Husband And Toddler Son. What Can Be Done?

Location: Georgia

My sister - Francine

My BIL/her husband - Scott

His father/Sisters FIL - Jude

A couple of hours ago, I got a call from Francine that Jude (history of violence but never reported or documented so legally irrelevant I believe but I will add details) had threatened Scott and their toddler, stating he would "find them" hell or high water.

All of this catalysted by Scott and Francine cutting off his family after comments like "We can take Baby whenever we want" and "You can't keep Baby from us" to "We will just come take Baby". They have text messages of Scott's mom stating that she will stand by Jude and he is going to come find them.

Jude has no criminal history that I'm aware of but he has beaten Scott and Scott's younger (adult) brother to the point that Scott's brother is now disabled. Jude has also murdered several dogs by strangulation and gun shot. Francine has constantly spoke out against this but Scott's family refuses to do anything about this. And honestly, no one has ever called the cops on him to my knowledge; they live in a very rural area and gun shots on private property arent uncommon so any shots heard wouldnt have been considered abnormal by anyone else living in the area.

I am livid. The abuse Scott suffered is vast and he refuses to let Baby be exposed but Jude and his wife have made it clear they don't care about boundaries or legality. How can Francine and Scott protect themselves and baby? Scott does have a firearm and Francine knows how to use it. Personally, I want them to just up and move some where far and safe like Scott's brother did. But is there any advice legally? I figure PD would need to create paper trails to get Jude off the street but Im so overwhelmed and worried that I don't know where to start. I think Francine and Scott just are frozen. They've stayed with my parents for a few days as Jude doesnt know where they live. But now theyre going home. Im venting now but Im just so scared. Any help appreciated.

Thank you