How do I report someone for harassment?

[ModaGenesis]

I have this new player coming around my Fashion Story boutique since yesterday, they keep leaving messages on my wall (and other players walls). One word messages, written multiple times.

Yesterday the message was "Hell" written over and over again on my wall. Today it was "death", again written multiple times in single word posts. I just went to their wall and they have disturbing messages on their own wall. See picture. Can someone please tell me how to report them? Thanks.

I am not accepting neighbors, please don't send requests. Thank you!