We live in a ground floor flat, our upstairs neighbours moved in earlier this year and have two kids (1 a couple of months old, 1 about two).
We barely know them but something has seemed strange since they came. I have had to knock upstairs for deliveries a few times and the wife won't come to the door if her husband isn't in. (She speaks some English, we have heard, but it clearly isn't her first language, so this may be why). I have never seen her leave the house without him. The husband has engaged in all sorts of low-level odd behaviour. Eg, he has entered our garden several times without permission even after we asked him not to. Other things too, which I don't want to put down incase too identifiable.
Although I find it odd, I would otherwise think nothing more of it. However, since our lodger moved out I have been working from home in the spare room a lot and this has much clearer sound channels to their flat. I heard some really nasty arguments - screaming, swearing - but again its their business not mine.
Until this week. I've heard plates being thrown and smashed and then screaming accompanied by really horrible wall shuddering thumps. On more than one occassion. It sounds like a room being trashed, or someone being hit/thrown against the wall and floor. It absolutely doesn't sound like regular household echoes. I think the screaming is hers as it sounds quite high pitched.
I hope this doesn't sound nosy neighbour, nor like I leap to conclusions because I've found some of his behaviour odd. I am genuinely worried for her (or whoever is the victim) and for their kids. But at the same time, I don't know anything, and I certainly don't want to make anything worse. I have thought about calling the police the next time I hear the noises, but am worried of a) repurcussions on victim b) being thought of as a time waster if it turns out to be nothing and c) any potential repurcussions on us. (It would be extremely unlikely if not impossible for someone from another flat to hear, due to the layout).
Not hearing anything now, BTW. Just wondering for next time I do. Grateful for your thoughts.