@MonsoonMadness I can understand that the violence can be really distressing. And although it isn't shown in great long detail, I think part of the reason for showing it at all, is not just for the crime plot, but to show what Catherine has to deal with, if not every day, but frequently. Maybe this is where her rather strange humour comes from.
But all in all I think the developing story is worth sticking with, and quite honestly when there is violence I often cover me eyes and rely on dialogue returning to then start watching again.