What to do if you suspect domestic violence at your neighbours?

I’ve got new neighbours who moved in the townhouse next to me two weeks ago. I moved in five years ago and never had any noise issues.

Since they moved there’s been an incredible amount running up and down the stairs, stomping of feet, slamming doors, yelling, little kids running around outside at 11pm. The noise goes well past midnight.

I’m in a block of three townhouses with my unit in the middle. My neighbours on the other side are also wondering what’s going on.

Obviously I want to complain about the noise however if their domestic violence going on that potentially cause the issue to escalate. I also don’t want to allege something only to find out I have incredibly noisy neighbors.