These kids need help

I'm like 99% sure my neighbors are abusing their kids. The mom and (I thinn) dad are always fighting and screaming at each other, calling each other names and threatening to kick each other out. I don't know who's paying the bills because they both threaten each other.

The mom, daily, screams at her kids so loud we can hear her through the walls. I assume she hits them because they scream quite often, and not just in a normal sobbing way, like pained, bloodcurdling screams. Things are always bumping around in their house, hitting the walls so hard it causes our metal wall decorations to audibly rattle. When we see the kids outside, they're always really shy and well behaved (so there's no reason for her to be screaming at them at the top of her lungs so often), and the mom almost always looks pissed, sometimes pulling them by their wrists or the collars of their shirts. She only sometimes tries to act as if nothing is wrong when she grabs her kids.

I don't know what to do, as CPS is notorious for being horrible. I wanna know if there are other avenues I can pursue to get these kids help